754 SPECIAL HISTOLOGY. 



becomes blended with the capsule of that body. In doing this it splits 

 into two lamellce, a posterior (v), which is blended with the capsule of 

 the lens a little behind its border, and cannot be traced further, so that 

 beyond that point the posterior wall of the lenticular capsule and the 

 vitreous body are directly in contact ; and an anterior (u) connected 

 with the ciliary processes, the zonula in the more restricted sense, 

 which is attached to the capsule of the lens a little in front of its margin. 

 Between the two lamellce and the border of the lens, there is left a space 

 surrounding the latter in an annular manner, and, in a transverse sec- 

 tion, of a triangular form the canal of Petit; which, though con- 

 taining a little clear watery fluid, yet during life is very narrow, inas- 

 much as its anterior wall or the zonula Zinnii so long as it is continuous 

 with the ciliary processes, like them presents the aspect of a much pli- 

 cated membrane, and consequently is brought into close approximation 

 with the posterior wall, at as many points as there are ciliary processes. 

 These folds, however, are still visible where the zonula, quitting the 

 ciliary processes, is continued independently upon the border of the 

 lens, as a part of the posterior wall of the posterior chamber of the eye ; 

 and it is therefore attached to the capsule, not in a straight but in a 

 slightly undulating line. 



With respect to the structure of the parts in question, much pains 

 have recently been bestowed upon the elucidation of that of the proper 

 vitreous body ; although it cannot be asserted that at present the truth 

 has been arrived at. Briicke's view, according to which the vitreous 

 body, like an onion, consists of concentric lamellae parted by a gela- 

 tinous fluid, was contradicted by Bowman, who has shown, that the con- 

 centrated solution of acetate of lead used by Briicke for the exposition of 

 these lamellce, produces the appearance of lamination not only on the 

 superficial surface but also on that of any section whatever, but without 

 rendering true lamellae manifest. Hannover's opinion, according to 

 which, after treatment of the vitreous body with chromic acid, numerous 

 dissepiments are found in it, running from the surface towards the axis, 

 so that in a vertical section a number of " rays" are perceptible pro- 

 ceeding from the central point, and the whole resembles an orange laid 

 open, appears to have more in its favor, inasmuch as, at any rate, the 

 vitreous body of the new-born child, according to Bowman (Lectures, p. 

 100, and Fig. 5, p. 97), when treated with chromic acid, very distinctly 

 exhibits an areolated aspect of the kind described, but it should be re- 

 marked that from the same author's observations, the conditions are 

 widely different in the eye of the adult, for, in this instance, in chromic 

 acid preparations, a few concentric lamellce are found externally, to 

 which succeed very irregular radiating septa, and lastly an irregular 

 central cavity. If to this it be added that these lamellce formed by 

 chromic acid also cannot be demonstrated as true membranes, and that 



