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cipal objects of the present communication is to point out, that in 

 some of the Reptilia, namely, the frog, toad, boa and common English 

 snake, the posterior layer of the capsule of the lens is capable of 

 being injected in animals of all ages. 



In these reptiles, it is worthy of notice, that the crystalline lens is 

 of a spherical shape and of large size as compared with the chambers 

 of the eye in which it is enclosed. 



In the boa (Python tigris) as shown in Plate II. fig. 1, the capilla- 

 ries of the posterior layer of the capsule are injected, and instead of 

 there being only one or two vessels passing through the vitreous hu- 

 mour to supply it, there are four, the two smallest, in all probability 

 being arteries, and the other two of larger size, veins ; the capsule it 

 will be seen does not extend much farther over than half the surface, 

 or what may be termed the equator of the lens, and appears to be 

 very loosely attached to it, the free margin projecting some little dis- 

 tance from its surface. The capillary net-work is very delicate, and 

 in arrangement is quite different to that found in the eyes of foetal 

 mammalian animals. 



In the common English snake {Coluber natrix) the vessels of the 

 capsule are small and very numerous, and the capsule itself extends 

 a little beyond the equator of the lens, its free margin being formed 

 by a large vessel, probably a vein, which surrounds nearly the whole 

 circumference of the capsule and terminates in one of the vessels of 

 the iris ; the vessels of the capsule, when removed and laid flat, very 

 much resemble a basket : in this animal there appears to be only one 

 vessel, probably an artery to supply the capsule. 



In the frog and toad, the same arrangement of parts is to be seen, 

 except that in both these animals, especially in the toad, the vessels of 

 the capsule are much fewer in number, and very much larger in dia- 

 meter, than in the two preceding specimens ; the large vein surround- 

 ing the free margin of the capsule is present in both, and if the lens 

 be removed from the choroid, the large vessel must be divided before 

 it can be separated from the iris ; in fact, the strength of this vessel 

 is such, that if the iris be held up by a pair of forceps, the lens will 

 be found suspended from it. 



Before quitting the subject of the vascularity of the posterior layer 

 of the capsule of the lens, it will be as well to point out in this place 

 another peculiarity which I have observed in the boa and snake, viz. 

 the vascularity of the thin transparent layer of skin covering the eye 

 of these animals. A specimen of this kind from the boa, is repre- 

 sented in Plate II. fig. 2 ; the vessels are of large size, and their mode 



