Zoological Society. 45 had again been directed to the peculiarities of the organs of vision in the male sex. He had already shown that these individuals pos-sess only ocelli at the sides of the head as well as on the vertex, but that these structures exist at precisely the same parts of the head as the ocelli and the compound eyes in the female, and consequently that there can be no doubt of their homology. These appearances, however, having led some to question the correctness of this, it be-came necessary, in order to judge aright of their nature, to consider what are the essential conditions of a structure which is specially destined for the appreciation of light. This consists, as already pointed out in Fishes, of a follicle or pit in the tegument of the head, coated with dark pigment, and receiving the distal termination of a particular cerebral nerve, conditions which are precisely those of the ocelli, both of the sides of the head and of the vertex, in Antho-phorabia. The various modifications of the eye in insects, with re-gard to the form of the cornea, the depth of the chamber, and the presence of the choroid, and of the lens, with reference to the extent of field, and the focal distance, of vision, were pointed out, and the degree in which they exist in Anthophorabia mentioned, as coinciding with the peculiar habits of the insect. The structures in the male were thus shown, by the presence of cornea, chamber, choroid, and nerve, to be most indisputably organs of sight. The author referred J:--^ fro the binary origin of the nerve of the middle ocellus of the vertex, as formerly pointed out by him in his paper on Pteronarcys ; to the origin of ocelli in the same way as other dermal tubercles ; and to the imperfect eye-spots in the Scorpionidce being supplied with nervous filaments from the same optic nerve which supplies the recognised organs of vision in those animals. May 3, 1853. — R. Brown, Esq., President, in the Chair. Read a memoir " On the Vegetation of Buenos Ayres and the neighbouring districts." By Charles James Fox Bunbury, Esq., F.R.S.. F.L.S.. &c. ZOOLOGICAL SOCIETY. May 13, 1851.— John Edward Gray, Esq., F.R.S., in the Chair. The following papers were read : — 1. Observations on the Eye of the Mole, in a letter addressed to w. spence, esq., f.r.s. By John Dax-y, M.D., F.R.S. In a letter with which you favoured me some weeks ago, you made mention of Schiodte's ' Faunae Subterraneae Specimen,' and of the interesting discoveries described in it of several species of eyeless animals, the inhabitants of caves into which the sun's rays never penetrate, and where, in utter darkness, visual organs would consequently be useless.
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