The Zoologist/4th series, vol 6 (1902)/Issue 731/Biological Suggestions. Animal Sense Perceptions (cont.)

by William Lucas Distant

 

THE ZOOLOGIST

 

---

 

No. 731.—May, 1902.

 

---

 

BIOLOGICAL SUGGESTIONS.
ANIMAL SENSE PERCEPTIONS.

By W.L. Distant.

(Continued from vol. v. p. 338.)

 

When we undertake the consideration of nauseous or offensive smells as means of protection in the animal world, we are able, in some degree, to leave the region of hypothesis which environed us when discussing the question of similarity in sensory impressions in animal vision, and to arrive at negative evidence as to the universality of the sensations of smell. This question becomes most important in estimating the amount of protection afforded to animals by the possession of nauseous or offensive odours. It is unnecessary to recapitulate the many instances already recorded of this protective factor in the struggle for existence. It will suffice to mention, as examples of the phenomena, the immunity from attack possessed by the evil-smelling Skunk (Mephitis mephitica) in the Mammalia, and by the Danainæ, Acræinæ, and Heliconinæ among butterflies, in the possession of malodorous juices that can be exuded from the body. It is more than probable that this offensive attribute is much more prevalent than at present recorded: at the same time, to prove its efficacy, it is necessary to also establish some standard of appreciative nastiness in the smell-impressions of the animal world.^[1] Some animals possess a musky odour, which, though distasteful, can scarcely be looked upon as protective. The Giraffe possesses this quality, and Mr. Bryden relates that when following one of these animals, his horse, "hitherto the steadiest shooting pony in the world, had early in the run got wind of the strong musky odour which all Giraffes possess, and bored to the left hand, and I had a good deal of trouble to persuade him to keep straight."^[2] Mr. Thomson suggests that among animals, at least, these odours may serve as incense, or as stimulant—"but perhaps this usefulness is secondary."^[3] An analysis of the evidence, I think, tends to show that the protection thus afforded is partial, and not universal.

Among plants, the Virginian Creeper (Ampelopsis quinquefolia), so frequently planted to cover porches, palings, and walls, develops flowers in midsummer which are very industriously and eagerly visited by bees. The colour does not act as an allurement in this case, for the flowers have green corollas, are hidden away under the foliage, and cannot be seen even by good eyes at a little distance. Yet the bees fly thither from all sides in such a way as to leave no doubt that the flowers of the Ampelopsis can be perceived by them a considerable way off. "Since it is not their appearance, it must be their smell which announces their presence. But to men they appear to be quite scentless."^[4] This clearly goes to prove that the sense of smell is very differently developed in men and bees. The very smell of flowers is subject to variation in response to the nature of the soil. This was demonstrated by Dalibard ('Observations sur le Réséda à fleur odorante').^[5] He planted mignonette in different soils, using seeds from the same mignonette plant, possessing its well-known fragrance. While the seeds sown in rich garden soil became vigorous, and were well perfumed, the seeds sown in sandy soil produced plants which remained weak and small, and had no perfume. It even seems that the latter did not acquire any odour when transferred to rich garden soil. "Similar facts have since been repeatedly observed and noticed."^[6] Another kind of secretion is that of strong scented ethereal oils. Species of Artemisia are characteristic plants of the deserts of Africa and Beluchistan; Pulicaria arabica has a particularly powerful odour. "Since Dr. Tyndall has shown how minute quantities of such oils diffused through the air are capable of arresting radiant heat, it has been suggested that this is one of the many resources to which desert plants appeal, in order to reduce the ill-effects of the heated atmosphere which surrounds them; and, just as the presence and quantity of opium, hasheesh, aconitine, &c, secreted by plants vary greatly with the climate, so it is reasonable, in the absence of strict investigations, to assume that these oils are in an excess through the intense heat and other conditions of the climate of deserts."^[7] This appears to have been first suggested by Dr. Volkens,^[8] and Mr. Henslow would further apply the suggestion to odoriferous plants growing at high altitudes.^[9] These observations or suggestions cannot, of course, have any application beyond the areas mentioned, and, if correct, tend to prove that scents emitted by plants may have other purposes besides those of animal attraction, and again inculcate the necessary caution against concluding that a quality many times observed to have an attractive purpose is necessarily fulfilling that function in all cases. The exhaustive and eloquent summing up of a brilliant judge may excite the admiration of the lounger in court, but does not necessarily have that effect on the litigant whose case it demolishes. Because a plant exhales an offensive odour, it is not less attractive to some insects. In Borneo, Mr. Burbidge found a large amorphophallus bearing fetid flowers; on cutting one of these open he found its basin "half-full of ants of two kinds, and numerous small black coleoptera were running about in the spathe."^[10]

The appreciation of scents and odours by mankind is not of universal similiarity, but varied and capable of artificial distortion. The sense of smell is generally considered as more highly developed in savage than in civilized races. Nevertheless, as Darwin has observed, it does not "prevent the Esquimaux from sleeping in the most fetid atmosphere,^[11] nor many savages from eating half-putrid meat.^[12] Many such people who have acquired for generations the habit of eating half-decomposed meat positively enjoy these odours. "What you take for a stink, a Hottentot, if you will believe him, receives as the most agreeable perfume."^[13] Even savages differ in this respect, when residing on the same island. The seaboard natives of most of the large islands of the New Hebrides differ in language from the Bushmen of the interior, and look with much disgust on the latter, among whom the family and dogs lived in such dirt, that a native of the coast told Lieut. Somerville that of the Bushman, or "Man-bush," as spoken there, "'e shtink plenty," not leaving the "house," he said, even to answer the calls of nature.^[14] I well remember, not so many years ago, having, on one of my rambles in the Transvaal, come across a number of Kafir women merrily cutting up a deceased ox on the veld, and I equally remember how I fled to windward of the scene. According to Cameron, the Manyuema not only eat the bodies of animals killed, but also of people who die of disease. "They prepare the corpses by leaving them in running water until they are nearly putrid, and then devour them without any further cooking. They also eat all sorts of carrion, and their odour is very foul and revolting."^[15] In describing the abode in Borneo of some Malay ladies "of quite the highest aristocracy," Mrs. Pryer states:—"The ground underneath the house (for all houses in this country are built on piles) was in a most horrible and unsanitary condition, being wet with green slime, and all the refuse from the house—fish-scrapings, potato-parings, and everything else—being got rid of through the open flooring above, and had putrified, and created a most evil smell; yet here were these people living above in utter unconcern, just as though deprived of the senses of sight and smell."^[16] Even the contents of the repulsive musk-glands of the Alligator, as found in the Madeira river of Brazil, are, according to Keller, mixed with a little rosewater, and serve to perfume the raven-black tresses of the elegant Bolivian ladies at Santa Cruz de la Sierra and Cochabamba, in spite of, or rather by reason of, their strong scent, which gives the headache to all save these strong-nerved Señoritas.^[17] In Damara Land the women wear necklaces, "the beads of which, Dokkie informed us, were made from the kidneys of the Meerkat, or other small animals, compared with whose odour that of the Polecat is mildness itself."^[18] Mr. Bailey, in the Congo Free State, had to prevent his Kroo boys from stopping his canoes to secure the putrid flesh of a blown-out dead Crocodile, which emitted a most fetid odour. He writes:—"Many times after, when with other tribes in the interior, I remarked their preference for bad meat to fresh."^[19] The Coreans are described as extremely filthy in their habits, being commonly supposed never to wash their bodies. Amongst their staple food is Kimchi, which "is a dish peculiar to the country, and is made of turnips, chilies, and dried fish, soused in native vinegar. This mixture is kept in jars until it ferments, and is then eaten. It has a most atrocious smell—so atrocious, indeed, that I have never heard of an European being so bold as to taste the stuff."^[20] According to Guillemard, the natives of the interior of Kamschatka "prefer their fish in an advanced stage of decomposition."^[21] Mr. Stephens, of Ugi, told Mr. Guppy that at Ontong-Java, which lies off the Solomon Group, he had known natives to allow the carcase of a pig to remain buried in the ground until it was rotten, when they dug up their treasure, and enjoyed their feast under cover of the night, as though conscious of the depravity of the act. It was the strong odour which penetrated his dwelling that attracted the attention of Mr. Stephens to their proceedings.^[22] Besides the well-known fact of the peculiar odour appertaining to the black races as non-appreciated by ourselves, the American tribes have been known "to express dislike at the white man's smell."^[23]

Even among ourselves it is possible to soon ignore or even welcome an unpleasant odour. This is well illustrated by the way European residents in the East soon overcome their repugnance to the evil smell of that delicious fruit, the Durian (Durio zibethinus). Here we have a fruit which, were it distasteful, would be banished for its malodorous qualities from any decent habitation, but for its delicious properties is welcomed on the most aesthetic tables. A similar remark applies to the Jack-fruit (Artocarpus integrifolia). Mr. Nicholas Pike, describing his experience of this fruit, which is highly esteemed by the Brazilians at St. Domingo, near Rio Janeiro, states that, "when cut, we could not be tempted to eat, though assured it was very nice. Being blessed with an acute scent, we could not get over its disgusting smell of putrid meat; and, strange to say, the meat-fly hovers round it, just as if it were a piece of carrion."^[24] Nor can such a strange appreciation of disagreeable odours be confined to men of ordinary intellect. Goethe once nearly fainted when writing at Schiller's table from the effects of a dreadful odour that issued from a drawer. Schiller's wife stated that the drawer was always filled with rotten apples, because the scent was beneficial to her husband, and he could not live or work without it.^[25] According to Augustus J.C. Hare, throughout life "the senses of smell and taste were utterly unknown" to the late Dean Stanley.^[26]

May we not conclude that other animals may conquer their repugnance to an evil smell possessed by creatures of otherwise highly edible recommendations, and that odoriferous protection may prove of a highly partial and uncertain character? The Tiger, contrary to what has been generally believed, is not at all averse to putrid meat.^[27] Lions have a similar habit, as recorded by Gordon Cumming and Selous.

It is at least open to conjecture whether the nauseous smells emitted by some animals—such as even the Skunk—are appreciated with the same intensity by all their enemies and colleagues. Great caution is required in deciding from probability, unchecked by observation, as to the protection acquired by animals either by unpleasant odour or offensive armature. The Porcupine (Hystrix cristata) may serve as an example. Analogy and probability would lead one to suppose that this formidably spined creature would be left severely alone. But the Leopard is said to kill it by a blow with its paw on the head; whilst the Fisher Marten (Mustela pennanti) kills a large quantity of Porcupines by a bite on their unprotected bellies, and eats the body, notwithstanding the quills, numbers of which are often found in the skin and flesh of the Marten, who does not seem much inconvenienced thereby. It is also apparently quite erroneous to consider all glandular or other scents of animals as being of a protective character. The Beaver (Castor sp.) not only secretes in two abdominal elongated glands the well-known smelling, waxy, medicinal substance "Castoreum," but so appreciates it itself that traps for its destruction are actually and successfully baited with the article, which at the same time in no way prevents the murderous onslaught of its natural enemy, the Glutton (Gulo luscus). The same remark applies to the Musk-Shrew (Crocidura murina), which, as described by Mr. Ridley, at Singapore, "often perfumes the lower part of the house with its strong musky smell. Notwithstanding this, the dogs and cats constantly kill them, though, of course, they do not eat them."^[28] Höhnel refers to the peculiar musk scent of the Buffalo in East Africa, which "still lingered in the air" after some of these animals had passed.^[29] He also describes the flesh of these animals as having a "strong flavour of musk."^[30] Apparently the sense of smell possessed by hounds is far greater, or more finely appreciative, than that of our own. On the other hand, this sense in man appears to be highly developed, although, as we have remarked above, in different races, pleasurable and painful sensations are sometimes seen reversed. The merest trace in a gaseous form of a drop of oil of roses^[31] is sufficient to produce in our nostrils the impression of a pleasant odour. The smallest particle of musk is capable of imparting its characteristic smell to our clothes for years, the strongest current of air being insufficient to drive it away; and Valentin has calculated that we are able to perceive about the three-one-hundred millionth of a grain of musk. The delicacy of our sense of smell thus far surpasses that of the other senses.^[32] If, on the other hand, the evil smelling properties of the Skunk^[33]—the enfans du diable of Gabriel Sagard-Théodat^[34]—tend to make it avoided by animals who would otherwise seize it as prey, and its peculiar markings are held by many as constituting "warning colours," thus increasing its protection; these same all-pervading odours must serve to advertise its presence and alarm its own prey, such as Mice, Salamanders, and Frogs, unless these animals are deficient in this sense perception. This seems evident when we read that the smell "is so durable, that the spot where a Skunk has been killed will often retain the scent for days, or even weeks; indeed, Audubon relates that at one place where a Skunk had been killed in the autumn, the odour was quite perceptible in the following spring, after the snow had melted."^[35] Frank Buckland relates that a brother officer, just returned from an American trip, told him that one day, as the train was rattling along at a great pace, "all of a sudden a most terrible smell came into the carriage. 'Oh! that's nothing,' said a passenger; 'we have just run over a Skunk'—which was the case. The Skunk's smell kept up with the train for many miles, though it was going at express pace."^[36] A species of the same animal (Mephistis patagonica) was killed by Mr. Cunningham's party in Patagonia, and the cap of its destroyer, which had happened to come in contact with the animal, "was for ever afterwards rendered useless."^[37] Dr. Leith Adams remembered driving one dark night, along a highway, when the effluvium of a Skunk was perceived for nearly two miles.^[38] Dr. Merriam describes it as "slow in movement and deliberate in action, and does not often hurry himself in whatever he does. His ordinary gait is a measured walk, but when pressed for time he breaks into a slow, shuffling gallop."

This slow-moving creature, emitting this awful stench around it, must necessarily give an early alarm to all animals whose business it is to get out of its way, and thus by a principle of compensation the advantages acquired by protection from enemies are, by the same special means, discounted by the greater difficulty of procuring food.^[39] For if, as is well known, the offensive secretion of the Skunk is only emitted from the glands^[40] when the animal is attacked or irritated, an odour so powerful as above described cannot fail to have become to a great extent distributed about its own pelage.^[41]

The odour of musk is frequently a purely sexual character in animal life. Girard has always observed that the musky odour which is emitted by two species of Sphinx moths is peculiar to the males.^[42] During the season of love a musky odour is emitted by the submaxillary glands of the Crocodile, and pervades their haunts.^[43] Dr. Junker found that the deck of the steamer on which he travelled up the Blue Nile was for some days pervaded by a musky odour after a wounded Crocodile had been despatched thereon.^[44] According to Mr. Ramsay, writing on the Australian Musk-Duck (Biziura lobata), the smell which the male emits during the summer months is confined to that sex, and in some individuals is retained throughout the year; he had never, even in the breeding season, shot a female which had any smell of musk.^[45] In the Australian Echidna, "during the rut, both sexes produce a most conspicuous odour, which is probably destined to favour the mutual approach of the animals, and enhance sexual excitement.^[46]

In some moths—Bombyces and Noctuas—the sense of smell is developed to an extraordinary degree. "Sugar" can be found by the "Owl Moths" in the darkest night. Three female B. quercus, each in a cage of perforated zinc, were placed in a leather bag on a certain July 19th. On the 20th they were taken out. The bag had a sea-trip, but males continued to assemble to it for twelve days afterwards.^[47] Even an empty pupa-case from which a female moth has escaped has been known to retain the attractive power for some time after the exclusion of the moth.^[48] Clearly, these facts prove two things—that Lepidoptera possess the sense of smell, and that some species, at any rate, depend on this sense in "assembling." They are the foxhounds, as it were, in Lepidoptera; they course by scent, as undoubtedly butterflies and many Geometers find their mates by sight.^[49]

In Java, according to Raffles, the Wild Pigs have so violent an aversion to the smell of urine, that the plantations are protected from their ravages by the practice of suspending rags impregnated with the fluid at small distances around the boundaries.^[50] We do not understand, or rather cannot give an adequate reason, why the marine worm-like creatures Balanoglossus, long buried in the sand of the sea-shore, "exhale a peculiar odour resembling that of the chemical substance termed iodoform.^[51] Again, the aquatic beetles Gyrinus, when handled, "give off a milky fluid of unpleasant odour from nearly all the joints of their body, but especially from the fore and hind edges of the thorax. The scent is rather like that given off by Cockroaches."^[52] "When a Dytiscus is captured, it often discharges a milky fluid from the thorax, just behind the head. The fluid smells like sulphuretted hydrogen.^[53] The Y-shaped "horn," which can be projected from near the head of the larva of Papilio machaon, is the source of a powerful odour of fennel—one of the food-plants of the caterpillar.^[54] The scents emitted by insects cannot be always estimated as of a "protective" character. Barrows and Schwarz have stated that "it would seem that Crows have a predilection for insects possessing a pungent or otherwise strong taste or colour." This is exemplified by the prevalence of Carabidæ (among them the often-recurring genus Chlænius possessing a peculiar odour), coprophilous or necrophagous Coleoptera (Silphidæ, Histeridæ, and Scarabæidæ, Laparosticti), ants, and more especially by the almost constant occurrence of certain species of the heteropterous family Pentatomidæ. "It seems probable that the strong odour or taste of these soldier bugs is the reason why they are so eagerly sought by the Crows."^[55]

Gilbert White recorded an instance which appears to have a "protective" explanation. "I knew a gentleman who kept a tame snake, which was in its person as sweet as any animal while in good humour and unalarmed; but as soon as a stranger, or a dog, or cat came in, it fell to hissing, and filled the room with such nauseous effluvia as rendered it hardly supportable."^[56] The same author remarks that "odours also appear to serve among animals as individual recognition signs. After ewes and lambs are shorn, there is great confusion and bleating, neither the dams nor the young being able to distinguish one another as before. This embarrassment seems not so much to arise from the loss of the fleece, which may occasion an alteration in their appearance, as from the defect of that notus odor, discriminating each individual personally; which also is confounded by the strong scent of the pitch and tar wherewith they are newly marked; for the brute creation recognize each other more from the smell than from the sight; and in matters of identity and diversity appeal much more to their noses than to their eyes. After sheep have been washed there is the same confusion, from the reason given above."^[57] It is certain that fishes possess the faculty of perceiving odours, and that various scents attract or repel them. A mangled carcase or fresh blood attracts Sharks, as well as the voracious Serrasal monoids of the South American rivers.^[58] However, according to Bateson, "the range of taste and smells which fishes are capable of perceiving seems to be very small. Conger are equally willing to eat a piece of Squid or Pilchard, if it is covered or smeared with spirit, trimethylamine, turpentine, iodoform, camphor spirit, cheese of various sorts, anchovy extract, or Balanoglossus, as if it had been unpolluted. On the other hand, they will refuse cooked or tainted food, and food which has been soaked for a few moments in dilute acids. The same remarks apply generally to other fishes."^[59]

Some Millipedes possess odoriferous glands emitting a disagreeable odour, due to the secretion of a fluid containing prussic acid. Mr. Pocock considers this "no doubt serves as a protection against birds, ants, &c, to these otherwise defenceless creatures." But, he adds—"in a Hornbill's nest in the British Museum, the plaster used to block the entrance is largely composed of crushed fragments of a large Spirostreptus."^[60] The same author states that a Solpuga, "which frequents houses in Denver, Colorado, is said to be of service to mankind on account of its partiality for bed-bugs, a fact of some interest, as showing that the strong stench of cyanide of potassium emitted by these parasites is no protection against the attacks of the Solpuga."^[61]

The theory as to the warning colours of the Skunk presents some difficulties.^[62] It was first proposed by that philosophical observer, Mr. Belt, in his 'Naturalist in Nicaragua,' wherein he described that animal as going "leisurely along, holding up his white tail as a danger flag for none to come within range of his nauseous artillery." A similar observation was subsequently made by Mr. Wallace in North America, who reaffirmed the theory, and explained its cogency by the argument that for such animals it was "important that they should not be mistaken for defenceless or eatable species of the same class or order, since in that case they might suffer injury or even death before their enemies discovered the danger or the uselessness of the attack."^[63] But the American Mink (Mustela vison)—as is the case with Minks generally—is described by Dr. Coues as second only to the Skunk in the possession of an extremely offensive effluvium, and yet it is of a more or less uniform coloration, and certainly is provided with nothing that can be described as "warning colours." And although the Malayan Badger (Mydaus meliceps), which possesses an extremely evil odour, is somewhat similarly marked as the Skunk, and with the tip of its short stumpy tail whitish, it is described as a purely nocturnal animal. Gymnura rafflesi is another animal generally considered as nocturnal in its habits, and with the terminal third of its rat-like tail usually white. According to Mrs. W.P. Pryer, in Borneo, the smell which this animal emits is insufferable, and hangs about for a long time; it is so overpowering, "that I have once or twice awakened from a sound sleep owing to one of these animals having simply passed below the house."^[64] If the colour of the Skunk is a product of Natural Selection, slowly acquired for protective—i.e. in this case, warning—purposes, it is at least surprising that other nauseous animals are not similarly protected. An equally probable suggestion, that of inherited intelligence on the part of its enemies is as likely to be the explanation. In fact, there is nothing to prove that its scent alone is not the deterrent quality, and that its bright colours are due to at present unknown causes, and serve unknown purposes.

Some brightly coloured animals have no warning colour or other protection, but trust to their own intelligence to avoid danger. Thus "the bright colour of the male Golden Oriole renders it peculiarly liable to be attacked by the Sparrowhawk, and in such a contingency the Oriole does not trust to his Thrush-like flight enabling him to elude his tormentor in the open, but on the earliest opportunity seeks refuge in the densest thicket available as cover."^[65] The Rose-coloured Pastor, with the back, breast, and sides of an exquisite pale pink, is observed in its continental haunts to frequent trees or shrubs bearing rose-coloured flowers, such as the blossoms of the pink azalea, among which the birds more easily escape notice.^[66]

Many plants owe their protection from the ravages of grazing animals to offensive odours, which to ourselves are unappreciable while the leaves are intact, and these apparently possess no warning colours, or, at all events, none of those glaring hues on which the theory is founded. These, however, are avoided by the animals from whom protection is required, and who have either learned to distinguish the plants by their appearance, or have a greater delicacy of smell than ourselves. Grazing animals also avoid plants furnished with stinging hairs, which certainly seems due to observation, and probably inherited experience. The European nettles (Urtica dioica and U. urens) are generally left alone, and how much more so the U. stimulans of Java, the U. crenulata of India, and U. mentissima of Timor, whose stinging hairs are capable of producing severe attacks of tetanus as by snake-bites.^[67] These plants, however, seem to have developed no prominent warning colours as understood by the theory; while their protection is undoubtedly real and efficient. The theory of warning colours is a brilliant suggestion, but one which seems to demand of nature an unnecessary effort to supplement protective qualities already sufficient. The argument has been thoroughly advanced by Prof. Poulton, who gives as a typical example the larva of the Magpie Moth (Abraxas grossulariata), as a showy, self-advertising, inedible creature, regarding which "all observers agree that birds, lizards, frogs, and spiders either refuse the species altogether, or exhibit signs of the most intense disgust after tasting it."^[68] This caterpillar is very common in gardens, and other and previous observers (Jenner Weir, Butler, and, more cautiously and critically, Beddard) have advanced a similar opinion as to its more or less immunity from attack. But Prof. Plateau, of Ghent, has subjected the question to a thorough experimental investigation, and finds that A. grossulariata does not disregard means of concealment, that it is protected by no special nauseous flavour, and that it is readily attacked under suitable conditions by certain Vertebrata, Arachnida, Coleoptera, Adephaga, and insect parasites. He concludes:—"The results of this research go to prove that, in the case of Abraxas, conspicuous coloration does not possess the warning significance which has been attributed to it, and naturalists will do well to apply further experimental tests to other cases in which this explanation has met with a too facile acceptance."^[69] In the pages of this Journal, Mr. Page has recorded how both larvæ and imagos of this species were greedily eaten by the birds in his aviary;^[70] and Mr. Oxley Grabham has found the stomachs of Cuckoos "crammed with these obnoxious larvæ."^[71]

Although it is dangerous to state the factors of all animal psychology in the terms applied to our own, it is still as equally misleading to allow the theory of automatism to dominate our minds when observing the actions of other animals. Some of the most highly educated, as well as some of the most ignorant men contemn their other animal colleagues as speechless, and imply that articulate language as used by ourselves must be the only means for interchange of ideas, and this in face of the well-known contrary evidence afforded by "gesture language."^[72] And a similar error, or danger, appears to exist in the theory of "warning colours," as used for an explanation of a difficult problem in coloration. Some of the most brightly coloured fruits are edible, and so are gorgeous fishes, elegantly marked mammals, and brilliant birds. The evil smell of the durian does not prevent its being a favourite fruit to the Orang, as well as to man, nor does its hard and spiny envelope afford it protection.^[73] On the other hand, many fruits obtain an undoubted advantage by their edible qualities, their seeds passing intact through the bodies of birds and other animals, and thus being scattered far and wide. The well-known nutmeg (Myristica moschata) affords a good example. This fruit, with its red arillus of mace, which is exposed by the splitting of the outside envelope when ripe, is both aromatic in smell and not inconspicuous in appearance. Birds, especially the Nutmeg-Pigeon (Carpophaga aenea) devour this fruit with avidity, and by their involuntary dispersal of the seeds caused the spice-preserving Dutch considerable trouble. These protectionists compelled the native chiefs on the islands of Ternate, Tidor, Makian, &c, to destroy their nutmeg plantations, in order that there might be no competition with the produce of their own trees in Amboyna and Banda. They employed agents to see that this destructive process was vigorously carried out, but their efforts were considerably frustrated by the birds, who deposited seeds in unlooked-for spots and inaccessible positions. As Labillardière narrated:—"This circumstance made the Company resolve to settle residents in those islands, whose principal business it is continually to search for and destroy all the young spice trees they can meet with. But it also often happens that the seeds are dropped in situations so precipitous as to escape the most active vigilance."^[74] But here the theory "of warning colours" is discarded, and replaced by that of "edible or attractive fruits."

 

(To be continued.)^[75]

 

---

1. Mr. Beddard considers:—"Speaking broadly, it is safe to say that the sense of smell is much more highly developed in animals than the sense of sight" ('Animal Coloration,' 2nd edit. p. 177).
2. 'Gun and Camera in Southern Africa,' p. 308.
3. 'Study of Animal Life,' 2nd edit. p. 105.
4. Kerner and Oliver, 'Nat. Hist. Plants,' vol. ii. p. 206.
5. 'Mem. Math, et Phys. Acad, des Sci.' 1750, p. 95.
6. Cf. Varigny, 'Experimental Evolution,' p. 103.
7. Henslow, 'The Origin of Plant Structures,' p. 82.
8. Ibid. p. 116.
9. Ibid.
10. 'The Gardens of the Sun,' p. 233.
11. Cf. Nansen's graphic description of this fact ('First Crossing of Greenland,' new ed. p. 165).
12. 'Descent of Man,' 2nd edit. p. 18.
13. Kolben, 'Cape of Good Hope,' vol. i. p. 231.
14. 'Journ. Anthrop. Instit.' vol. xxiii. p. 365.
15. 'Across Africa,' vol. i. p. 357.
16. 'A Decade in Borneo,' p. 79.
17. 'The Amazon and Madeira Rivers,' pp. 76–7.
18. Baines, 'Explor. in S.W. Africa,' p. 149.
19. 'Travel and Adventure in Congo Free State,' p. 58.
20. H.S. Saunderson, 'Journ. Anthrop. Instit.' vol. xxiv. p. 307.
21. 'Cruise of the Marchesa,' 2nd edit. p. 69.
22. 'The Solomon Islands,' p. 92.
23. Tylor, 'Anthropology,' p. 70.
24. 'Sub-Tropical Rambles,' p. 18.
25. 'Conversations of Goethe,' Eng. transl. new edit. p. 289.
26. 'Biographical Sketches,' p. 25.
27. Cf. Gen. D. Hamilton, 'Rec. of Sports in S. India,' p. 175, et seq.; and Col. Pollok, 'Zoologist,' 1898, p. 157.
28. 'Natural Science,' vol. vi. p. 29.
29. 'Discovery of Lakes Rudolf and Stefanie,' vol. i. p. 125.
30. Ibid. vol. ii. p. 23.
31. Great variety is found in the scent of distinct roses. Kerner and Oliver state that the various species of the rose genus may be recognized at once by their peculiar scent. The perfume of Rosa centifolia is the one which in particular is understood by the rose-scent, but it is very different from that of R. alpina; and the latter, in its turn, is unlike any of the scents emitted by R. arvensis, R. gallica, R. indica, &c. R. nasterana has a scent strongly resembling that of pinks, while R. lutea and R. punica are notorious for their disagreeable smell. Now the hybrid roses emit odours in which the scents of the parent species are merged together in a great variety of ways. Usually the scent of the stock predominates, and there is only a suggestion of the other. Sometimes, however, an entirely new scent is evolved from the fusion of the two, as in the case, for instance (according to Macfarlane), in Hedychium sadlerianum, the hybrid between H. gardnerianum and H. coronarium; and, again, in other cases, one of the component odours is intensified, and the other is extinguished ('Natural History Plants,' vol. ii. p. 566).—If we may consider the different scents as at all equivalent in number to the different races or varieties of roses, then we are face to face with a most complicated phenomenon; for, according to the previously quoted authorities, on an average, sixty newly-bred roses come into the market yearly; in the year 1889 the number even amounted to 115! A rose cultivator at Meidling, near Vienna, grows in his garden nearly 4200 different kinds of roses, and yet he is still far from possessing all the forms which have been produced in recent times (chiefly by French growers) by crossing one with another. According to his estimate, the number of tea and Indian roses alone is nearly 1400, and the total number of all the different roses which the trade has produced up to the present day (1895) amounts to 6400. It would certainly appear that the scents emitted by plants are not universally of an attractive purpose. "The scent which the mosses exhale is found in no other group of plants. The same is true of ferns" (ibid. p. 615).
32. Bernstein, 'The Five Senses of Man,' p. 289.
33. The North American Skunks have recently been studied and their zoological position revised by Arthur H. Howell ('North American Fauna,' No. 20, 1901), who has placed them in the genus Chincha, Lesson, and enumerated seventeen species or subspecies.
34. 'Histoire du Canada,' p. 748 (1636).
35. Cf. W.K. & T.J. Parker, 'Cass. Nat. Hist.' vol. ii. p. 196.
36. 'Curios. Nat. Hist.' Pop. edit. ser. 2, p. 119, note.
37. 'Notes, Nat. Hist. Strait of Magellan,' p. 110.
38. 'Field and Forest Rambles,' pp. 66–7.
39. The same remark applies to at least some of the Australian snakes. The "Old Bushman" writes:—"There is a strong scent peculiar to the Australian snakes, and I have often smelt one long before I saw it" ('Bush Wanderings Nat.' p. 200).—On this point, Darwin, who seems to have anticipated most suggestions and objections bearing on his theory, must be quoted: "Natural Selection cannot possibly produce any modification in a species exclusively for the good of another species, though throughout nature one species incessantly takes advantage of, and profits by, the structures of others" ('Origin of Species,' 6th edit. p. 162).
40. The glands lie on either side of the rectum, and are imbedded in a dense gizzard-like mass of muscle, which serves to compress them so forcibly that the contained fluid may be ejected to the distance of four or five metres (approximately 13 to 16½ feet). Each sac is furnished with a single duct that leads into a prominent nipple-like papilla that is capable of being protruded from the anus, and by means of which the direction of the jet is governed (Merriam, 'Mam. Adirondack Reg. T.L.S. N.Y.' i. p. 76, 1882).
41. According to Mr. Hudson, the Common Deer of the Pampas (Cervus campestris) gives out—in the male—an effluvium quite as far-reaching, although not so abominable in character as that of the Mephitis?... Yet it is not a protection—on the contrary, the reverse,... and wherever Pumas are found, Deer are never very abundant. The Guachos, however, say it is protective against snakes ('The Nat. in La Plata,' pp. 159-60).
42. 'Zool. Rec' 1869, p. 347.
43. Owen, 'Anatomy of Vertebrates,' vol. i. p. 615 (1866).
44. 'Travels in Africa,' 1875–8, Eng. edit. p. 203.
45. 'Ibis,' n.s. vol. iii. p. 414 (1867).
46. Semon, 'In the Australian Bush,' p. 160.
47. J. Arkle, 'Entomologist,' xxvii. pp. 337.
48. Cf. J.W. Tutt, 'British Moths,' p. 53.
49. J. Arkle, 'Entomologist,' xxvii. pp. 337–8.
50. 'History Java,' vol. i. p. 57.
51. 'Roy. Nat. Hist.' vol. v. p. 573.—According to Mr. Bateson, as the disgusting smells emitted by various species of Balanoglossus may be thought to be protective, he tested various fishes with pieces of a single damaged specimen of B. salmoneus, which was dredged in Plymouth Sound. It was refused by both Mullet and Wrasse after trial, but was eaten by a Sole and by a Plaice ('Journ. Marine Biol. Assoc' (n.s.), vol. i. p. 247).
52. Cf. Miall, 'Nat. Hist. Aquat. Ins.' p. 33.
53. Ibid. p. 61.
54. Furneaux, 'Butterflies and Moths' (British), p. 140.
55. 'Bull. No. 6, U.S. Dept. Agric., Div. Ornith. and Mamm., 1895.' Cf. reprint in 'Indian Mus. Notes,' vol. iv. No. 2, pp. 86–91.
56. 'Nat. Hist. Selborne,' Harting's edit. p. 86.
57. 'Nat. Hist. Selborne,' Harting's edit. p. 317.
58. Cf. Günther, 'Introd. Study of Fishes,' p. 110.
59. 'Journ. Marine Biol. Assoc' (n.s.), vol. i. p. 247.
60. 'Roy. Nat. Hist.' vol. vi. p. 212.
61. 'Nature,' vol. lvii. p. 619.
62. The Skunk has its enemies, and is not so unmolested as has been stated. In Patagonia the Skunk is one of the most abundant animals. The traveller D'Orbigny wrote that in that country the Skunk formed the chief food of the Crowned Harpy Eagle; but, although D'Orbigny's statement is, according to Mr. Hudson, "pure conjecture," Mr. Hudson admits that most of the Eagles shot by himself in Patagonia, including a dozen Chilian Eagles and one Crowned Harpy, smelt of Skunk. Pumas also sometimes commit the same mistake, for their fur in some cases smells strongly of Skunk (Beddard, 'Animal Coloration,' 2nd ed. p. 178).
63. 'Darwinism,' p. 232.
64. 'A Decade in Borneo,' p. 75.
65. H.A. Macpherson, 'Roy. Nat. Hist.' vol. iii. p. 355.
66. Jno. Watson, 'Poachers and Poaching.' p. 319.
67. Cf. Kerner and Oliver, 'The Nat. Hist. Plants,' vol. i. p. 442.
68. 'Colours of Animals,' p. 168.
69. 'Mém. Soc. Zool. France,' 1894, pp. 149–53.— An English abstract of this paper will also be found in 'Natural Science,' vol. vi. p. 82; and in Ent. Month. Mag. 2nd ser. vol. vi. p. 70.
70. 'Zoologist,' 1897, p. 169.
71. Ibid. p. 236.
72. This shows no advance on the teachings of Socrates, who, in his discourse with Aristodemus, observed:—"A tongue hath been bestowed on every other animal, but what animal, except man, hath the power of forming words with it, whereby to explain his thoughts, and make them intelligible to others" (cf. G.H. Lewes, 'Philosophy of Socrates').
73. Mr. Hornaday thus describes this edible luxury:—"The fruit is very much the same in size and shape as a pineapple, but the entire outside is a bristling array of dark green conical spines, three-fourths of an inch high, and very sharp.... It is a painful matter to hold a durian except by the stem, and I would as soon have a six-pound shot fall upon me as one of them.... This wholly abominable pod smells even more offensive than it looks, the odour given off being like that of a barrel of onions at its most aggressive stage" ('Two Years in the Jungle,' p. 318).
74. 'Voyage in Search of La Perouse' (1792), vol. i. p. 408.—In South Africa the fruit of the Prickly Pear (Opuntia sp.) is eaten by Baboons, the seeds passing through their bodies, and being deposited in a ball of dung, often in the most inaccessible spots.
75. Although this second part finishes with "(To be continued.)", there were no further parts published (Wikisource-ed.).