12 



terior capsule give way, then the layer of the capsule may be retained 

 by the vessels connecting it with the iris, and so form the membrana 

 pupillaris. If a perfect specimen of membrana pupillaris, as shown in 

 Plate IV. fig. 1, be examined in situ, some of the vessels that con- 

 nected it with the posterior layer of the capsule, will be found lying 

 loose around the margin of the iris. It will be seen also from 

 the representation of the vessels of the anterior layer of the capsule 

 of the foetal wolf, in Plate III. fig. 2, and of the kitten, in Plate IV. 

 fig. 1, and of a foetal dog, in fig. 2, that the arrangement is not the 

 same in different animals ; the vessels of the human foetus are dif- 

 ferent from any of these, but most nearly resemble those of the 

 kitten in Plate IV. fig. 1. From what I understand of the struc- 

 ture of the membrana capsulo pupillaris of Henle, and from his de- 

 scription and representations of the vessels, the parts above described 

 as coating the lens, must be considered as identical with his so-called 

 membrana capsulo pupillaris ; but he does not appear to be aware of 

 the fact, that the anterior layer when separated from the posterior, 

 goes to form the membrana pupillaris of the older anatomists* 



The fact of the permanent vascularity of the posterior layer of the 

 capsule of the lens of Beptilia, as far as I can learn, is new to science, 

 and for this reason I have been induced to bring it before the So- 

 ciety, and at the same time to introduce a new method of printing 

 blood-vessels in colour ; the drawings in illustration of this subject 

 now exhibited, having been first made by Mr. Aldous, and subse- 

 quently printed by an improved process of Mr. Hulmandel. 



* Since this paper was read, my attention has been directed to the description of 

 an injected capsule of the lens of a young rabbit, in the Catalogue of the Museum of 

 St. Thomas's Hospital; and I am happy to find that the opinion both of Mr. Grainger 

 and Mr. Rainey coincides with my own, viz., that the anterior layer of the capsule 

 and the membrana pupillaris are identical. 



