LXIX.-PAPAYACEÆ.
This, though one of the smallest, is yet, in some respects, a very interesting order. The number of its species seem to amount to only 6 or 7, and form two genera, neither of which are considered of Indian origin. The Papaw tree, the only one met with in India, being introduced from America. This tree is usually supposed to be always diœcious and I have even heard the possibility of the union of the sexes on the same plant questioned. The prevalence of this opinion combined with the general acquaintance, in India, with the usual form of the tree, has induced me, in the accompanying figures, to present unusual forms, partly with the view of removing such erroneous opinions, but principally to illustrate a point in vegetable physiology not generally understood. I allude to power which vegetables possess, in particular circumstances, of developing organs which are usually suppressed. In the first of these plates we have an instance of a ramous specimen of this tree, to show, that though it rarely developes lateral buds, yet, that they exist in the axil of each leaf and are readily developed when the terminal one has been injured. The main trunk of this tree had been injured and many lateral buds are developed and now form vigorous branches. The next presents two panicles of male flowers every branch, of the larger of which, is furnished with one or more fertile flowers : the smaller is the usual form without fertile flowers : the former was taken in June from a tree growing in moist rich soil on the bank of a canal, in the then cool and humid climate of Quilon ; the other grew in Madras. The monoecious plant is also of frequent occurrence in the cool climate of Kandy in Ceylon, but I have never seen a single instance of the kind in the hot dry climate of the Carnatic. This fact affords a strong confirmation of the truth of an observation of Mr. Knight, that he could render melon plants much more prolific of fruit by cultivating them in a very cool atmosphere, almost every flower produced in such circumstances being fertile, while male flowers predominated in opposite circumstances. In the Papaw, this is accounted for by each male flower being furnished with an ovary, usually rudimentary, but which is yet capable of becoming fertile.
The Papaw is, except in the circumstances above mentioned, usually a tree without branches with a cylindrical succulent lactescent stem, of so very rapid growth that it often attains sufficient maturity to bear fruit within 18 months from the time the seed was sown. The leaves which are large digitately palmatifid on long hollow petiols without stipules, form a capacious tuft or crown on the apex : the male flowers form large drooping panicles while the females are nearly sessile.
" Flowers unisexual. Calyx minute, 5-toothed. Corolla monopetalous, inserted into the base of the calyx, in the male tubular and 5-lobed ; in the female divided nearly to the base into five segments. Stamens 10, inserted on the throat of the corolla : anthers introrse, 2-celled, bursting longitudinally ; those alternate with the lobes of the corolla on short filaments, those opposite to the lobes sessile. Ovarium free, 1 -celled : ovules indefinite: stigmas sessile, 5 lobed, lacerated. Placentas 5, parietal. Fruit succulent, indehiscent, 1 -celled. Seeds indefinite, parietal, enveloped in a loose mucous coat : testa brittle, pitted. Embryo in the axis of
a fleshy albumen : radicle slender, turned towards the hilum : cotyledons flat. ——Trees without branches. Leaves alternate, lobed, on long slender petiols."
AFFINITIES. Jussieu originally arranged Carica and the genera now referred to Passifloreae as allied genera, under Cucurbitaceae ; remarking, that they were principally distinguished by their superior ovary, he like others considering the Peponida as a 1 -celled parietal fruit, and thus placed them between Cucurbitaceae and Urticaceae. Their affinity with the former is still asserted but not with the hitter. In my remarks on Cucurbitaceae I have shown that in common with all other parietose orders they can have no very close affinity with that family on account of the wide difference in the structure of their ovary. With Passifloreae they are closely connected by one character, common to both, but not constant in all the species, the placentas, namely, being spread over the whole surface of the carpels in place of confined to their lines of junction. The seed, which I have not seen well described, may perhaps afford other characters. It is enclosed with a quantity of thin mucous pulp, in a hyaline sack, arillus ? is of an oval shape, the testa thick, exteriorly black and of a loose cork-like texture, rough and corrugated internally firmer, polished within. Sir W. J. Hooker describes it, as about the size of a hemp seed, " roundish, compressed, almost black, but covered with a transversely wrinkled, loose, greyish, skin or arillus, and enveloped in mucous." This description does not quadrate with specimens now before me — the testa of which evidently consists of 2 layers, an outer one spongy or suberose, furrowed, and an inner denser and polished within, enclosed within a loose transparent, sack but no proper arillus. The seed itself agrees in structure with those of both Euphorbeaceae and Urticaceae, as does those of Passifloreae, which however form only a remote affinity when not supported by characters taken from the ovary or mature fruit. I look upon Papay aceae as more nearly related to Passifloreae than to any other order, though sufficiently distinct.
GEOGRAPHICAL DISTRIBUTION. America is the native country of this order, which is only known in other countries as objects of cultivation, but as such, the Papaw has become widely distributed, apparently readily adopting itself to every variation of climate within the tropics.
PROPETIES AND USES. These are about the most curious of any yet met with in the vegetable kingdom, but so little known in India, that I am under the necessity of having recourse to the experience acquired in the West Indies to make them known. These accounts though rather too long for this work I shall not attempt to abridge, but introduce in the words of the originals. One circumstance 1 have observed, not mentioned by either, is, that the ripe seeds when chewed yield in a very marked degree the pungency and flavour of nasturtium or Indian cress. This flavour and taste is possessed by the seed proper, not the testa, which is insipid. The first of the following extracts is from the pen of Sir W. J. Hooker, published in the Botanical Magazine, Nos. 2898 99 — and the last from a paper by Dr. Holder, long a medical practitioner in the West Indies, published in the Wernerian Memoirs, vol. 3d page 245.
"The Papaw Tree is of rapid growth. ST. PIERRE probably spoke from his own knowledge, when he described VIRGINIA as having planted a seed, which, in three years' time, produced a trunk twenty feet high, with its upper part loaded with ripe fruit. It is for the sake of this fruit, mainly, that, the plant is cultivated ; but if the flavour were not better than that yielded by what ripened in our stove, I cannot recommend it as at all agreeable. Brown in his Natural History of Jamaica tells us, that " it has a pleasant sweetish taste, and is much liked by many people ; that, while young, it is commonly used for sauce ; and when boiled and mixed with lime juice and sugar, is not unlike, or much inferior to that made of real apples, for which it is commonly substituted." In the opinion of SLOANE it is not a very pleasant fruit, even when helped with pepper and sugar; and the more ordinary use, he adds, of this fruit. is before it is ripe, when, as large as one's fist, it is cut into slices, soaked in water till the milky juice is out, and then boiled and eaten as turnips, or baked as apples.
The juice of the pulp, according to DESCOURTILZ, in the Flore Medicale des Antilles, is used as a cosmetic, to remove freckles on the skin, caused by the sun ; and the negroes in the French colonies employ the leaves to wash their linen instead of soap.
As a medicinal plant, the Papaw Tree is particularly deserving of notice. HERMANDEZ long ago spoke of the milky juice of the unripe fruit as a powerful vermifuge ; which has been
confirmed by M. CHARPENTIER COSSIGNI, as mentioned in the Asiatic Researches, by DR. FLEMING (vol. ii. p. 162). A single dose, that gentleman says, is sufficient to cure the disease, however abundant the worms may be. Another French writer (POUPEE DESPORTES) recommends the use of the powder of the seed instead of the juice.
But the most extraordinary property of the Papaw Tree, is that which is related, first I believe by BROWNE, in his Natural History of Jamaica ; namely, that " water impregnated with the milky juice of this tree is thought to make all sorts of meat washed in it very tender ; but eight or ten minutes steeping, it is said, will make it so soft that it will drop in pieces from the spit before it is well roasted, or turn soon to rags in the boiling." Mr. NEILL mentioned this circumstance more fully in his interesting Horticultural tour through Holland and the Netherlands ; and it has repeatedly been confirmed to me by gentlemen of this country who have been long resident in the West Indies, and who speak of the employment of the juice for such a purpose as of quite general occurrence; and more, that old hogs and old poultry, which are fed upon the leaves and fruit, however tough the meat they afford might otherwise he, it is thus rendered perfectly tender; and good too, if eaten as soon as killed, but that the flesh very soon passes into a state of putridity.
Whether this power of hastening the decay of meat be attributable to the animal matter or fibrine contained in the juice of the Papaw or not, I will not pretend to say, but the presence of such is a fact scarcely less wonderful than the property just alluded to. Two specimens of the juice were brought from the Isle of France ; in the one the juice had been evaporated to dryness, and was in the state of an extract; in the other, the juice was preserved by being mixed with an equal bulk of rum. " Both were subjected to analysis by VAUQUELIN. The first was of a yellowish-white colour, and semitransparent. Its taste was sweetish. It had no smell, and was pretty solid ; but attracted moisture when kept in a damp place. The second was reddish -brown, and had the smell and taste of boiled beef. When the first specimen, was macerated in cold water, the greatest part of it dissolved. The solution frothed with soap. The addition of nitric acid coagulated it, and rendered it white ; and when boiled, it threw down abundance of white flakes. When the juice of the Papaw is treated with water, the greatest part dissolves ; but there remains a substance insoluble, which has a greasy appearance. It softens in the air and becomes viscid, brown, and semitransparent. When thrown on burning coals it melted, let drops of grease exude, emitted the noise of meat roasting, and produced a smoke which had the odour of fat volatilized. It left behind it no residue. The substance was fibrine. The resemblance between the juice of the Papaw and animal matter is so close, that one would he tempted to suspect some imposition, were not the evidence that it is really the juice of a tree quite unquestionable."
This fibrine had been supposed, previously, to belong exclusively to the animal kingdom : but it has since been found in other vegetables, especially in Fungi.
" The effects of the juice of the Carica Papaya, or Papaw Tree, whether of the fruit, stem, or leaves, or even of the exhalation from the plant, in lessening the cohesion of the muscular fibre, and acting on the fibrin of the blood, are matters of common observation in the Island of Barbadoes ; the inhabitants availing themselves of this property, to render more delicate, when thought necessary, the beef, mutton, pork, and poultry of their tables. If the milky juice, which is readily procurable by incision into the tree, or unripe fruit, be thoroughly rubbed on the flesh of a tough or old animal, and the animal be cooked by roasting, the fibres so completely lose their cohesion, that the flesh will fall from the bones, or be separated by the slightest force. If a smaller quantity of the juice be used, the flesh will be rendered tender; but so great is the effect, and so difficult is it to ascertain the degree to which it may be carried, if the milky juice be directly applied to the flesh, that another and more certain mode has been resorted to, tor procuring the inteneration of the flesh of different animals. By simply suspending the animal to a bough of the tree, for a space of time proportioned to the size of the animal, or of the joint of meat, the flesh is found to be sufficiently intenerated. A particular friend of mine, was in the constant habit of having his meat so prepared for his table, and was particular enough (or thought it necessary), to use his watch to regulate the time of suspension.
This quality of destroying the cohesion of the muscular fibre, probably resides chiefly in the milky juice, or in the vapour, which, I conjecture, is exhaled from the tree, since the boiled fruit, when given to animals, does not produce this effect to such a degree as to be sensible. The fruit is used by all ranks of people ; cooked in its unripe state, as a vegetable ; or served up, when ripe, as part of the dessert, with perfect impunity.
It is a common practice with some of the farmers of the Island of Barbadoes, to give an infusion of the raw fruit ; or, to speak more exactly, a diffusion of the milky juice in water, extracted from the fruit, to horses, with a view, as they express it, " of breaking down the blood ;" and it is a fact, well established, that if given to a horse, whose blood exhibits the cupped buffy coat, it will, after some time, produce a loose coagulum, and reduce the inflammatory symptoms which gave rise to it. I understood, from my friend, the late Dr Jones, of Barbadoes, well known in this University, by the publication of an ingenious experimental Thesis, that he had ascertained this to be the effect of the papaw juice on a horse, which had cough. and whose blood was buffy; and this account has very recently been confirmed to me, by a near connection of Dr. Jones's, a gentleman who formerly lived with him, and who is at present a residenter in this city, as a student of medicine.
That this remarkable effect is independent of putrefaction, or of a process verging to putrefaction, is rendered extremely probable, by the fact, that it is not confined to dead muscular fibre, but is produced on the circulating blood ; or, at least, on one of its constituent parts. At the same time, the consequence of this effect will no doubt be by its mechanical operation, to promote and hasten putrefaction, on account of its destroying the cohesion of the flesh, and separating the fibres. This is a fact so well known to the housewives of the colony, that they will not purchase, for salting, pork which has been partly fattened on the boiled fruit of the papaw (a practice commonly followed by the negroes of the colony), on account of the flesh not being sufficiently firm for salting ; or, at least, because they find, by experience, that, after having undergone the process of salting, it will not keep as long, or as well as flesh of hogs "which have been fattened on any other aliment. What is remarkable, this effect is observable, although the flesh of a recently killed animal, fed on the boiled papaw fruit, is not sensibly intenerated : For a society of gentlemen, who were in the habit of dining periodically with the late Governor of Barbadoes, Sir George Beckwith, fed several animals in this way, with a view to ascertain the effect on the flesh. We found, that when the animals so fattened, were served up, their flesh was not, to the taste, more tender than that of other animals at the table, fed in the common mode.
The health of animals fed on the Papaw, is not injured by that diet.
I may add, that the juice of the Papaw has been, by some, administered as a vermifuge to children, whether with marked success I am doubtful.
The chemical analysis of the juice of the Carica Papaya has given, in the hands of Vauquelin, some very curious results : from them, he draws the following conclusion.
" I think," says he " that there cannot beany doubt that the juice of the Papaw is a highly animalized substance; at least it possesses all the characters, and yields all the products of one. I confess that it has no perfect similitude with any known animal matter. Nevertheless, I believe that which it resembles most, is animal albumen ; since dried, it dissolves, like it, in water. Its solution is coagulated by heat, by the acids, by the alkalies, the metallic solutions, and the infusion of nut-galls. And, in fine, because, by distillation, it yields the same products as any animal substances whatever. It is not the animal nature of this substance which ought to surprise us ; for the juices of almost all plants contain some of it ; but its abundance and its purity in that of the papaw."
EXPLANATION OF PLATE 106.
Carica Papaya — female plant.
1. A full grown tree, presenting the unusual appearance of bearing several large branches, attributable to the terminal bud of the parent stem having been injured which caused the lateral ones to shoot.
2. A female flower, natural size.
3. Ovary and calyx, petals detached.
4. Portions of the stigma more highly magnified.
5. Ovary cut transversely.
6. Cut vertically — one-celled, the whole inner surface covered with ovules.
7. A seed enclosed in its sack or arillus.
8. The sack opened showing the seed.
9. Seed cut transversely, showing the embryo in the midst of a large albumen.
10. Seed cut vertically showing the embryo in situ.
EXPLANATION OF PLATE 107.
1. A panicle of flowers of Carica Papaya taken from a male tree, but in this instance having female flowers mixed.
2. A male flower split open, showing the 2 rows of stamens and abortive ovary in the bottom of the tube.
3. One of the female flowers detached and the petals forced open te show the ovary.
4. The same, cut open.
5. A Papaw taken from the same tree smaller than those produced on the female tree, but otherwise perfect.
6. The same cut vertically showing the seed in situ.
7- Portion of a panicle of male flowers the usual form.
8. Male flowers split open.
9 & 10. Back and front views of the stamens.
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CARICA PAPAYA (LINN.)
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CARICA PAPAYA (LINN.)