Page:The Zoologist, 4th series, vol 3 (1899).djvu/486

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THE ZOOLOGIST.

the external surface, there being a hilar area, a hilar scar, and a capitulum corresponding to the micropylar caruncle of such seeds as those of the castor-oil plant (Ricinus communis)."[1] The eggs of Phyllium crurifolium are a case in point. Henneguy states "that a prominent lozenge on the egg represents the surface by which the achene of an umbelliferous plant is united to the column, and that the micropyles are placed on this lozenge. As regards the egg-capsule, the same writer observes:—"Almost every botanist, on examining for the first time a section of this capsule, would declare that he is looking at a vegetable preparation."[2]

In Plant-life the same suggestions occur. The bladderworts (Utriculariæ) are carnivorous, and capture small crustaceans, larvæ of gnats, &c, by the aid of small bladders with orifices closed in each case by a valve, which permits objects to penetrate into the cavity of the bladder, but not to issue out of it. "The bladders of Utriculariæ, living in still water, look delusively like certain Ostracoda, especially species of the genus Daphnia. The bladder itself resembles the shell-covered body in size and form, and the bristles the antennæ and swimmerets of one of these crustaceans."[3] Small crustaceans are probably thus allured to their own destruction, and the bladderworts exhibit "aggressive mimicry." In the 'Botanical Gazette' for April, 1896, an interesting case ascribed to mimicry is described. The seeds of the "Philippine Island bean, from the coast near Manila, so closely resemble the quartz pebbles among which they fall, in shape, size, colour, lustre, hardness, and stratification, as to be indistinguishable from them except by a very close examination."[4]

Sometimes we read accounts of assimilative colouration, where it is difficult to see the raison d'être, if mimicry is propounded. Such an instance is given by Mr. Nicholas Pike:—"On my first visit to Round Island" (near Mauritius), "I captured a Scorpion of a bright green, just the colour of the leaves of the Jubæa palm it was disporting on. The creature was very active and defiant, and it was with difficulty I caught him."[5]

  1. In 'Zool. Results of Arthur Willey Exped.' pt. i. p. 78.
  2. 'Cambridge Nat. Hist.' vol. v. p. 271.
  3. Kerner and Oliver, 'Nat. Hist. Plants,' vol. i. p. 122.
  4. 'Nature,' vol. liv. p. 106.
  5. 'Sub-Tropical Rambles,' p. 162.