44 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 



same time dovetailing with each other and budding off cells to form 

 the inside of the lens (Figs. 7, 13). 



At the lower side of the lens, near the margin of the retina, the 

 cells of the lens are slightly indented or pushed inwards (Fig. 7, ind.), 

 I believe this to be due to the weight of the lens in the normal 

 position of the club, when the lens rests against the margin of the 

 retina and the capsule and adjacent tissue. 



Anticipating the description of the retina, it may here be added, 

 that the retina is formed from the inner half of the lens-retina sphere. 

 The cells of this portion of the sphere become differentiated into 

 prism cells, pyramid cells, and long pigment cells, while laterally, 

 beyond the margin of the vitreous body, they are differentiated into 

 pigmented iris cells (Figs. 7, 6a). 



Above are my results on the lens. Haake 2 speaks of the lens as 

 consisting of a cellular " Kern " with a covering of lamellated cells. 

 Carriere describes it as cellular and filled internally with a " Gerinsel," 

 or coagulation. Carriere and Haake are each in part right. Glaus 

 describes it as wholly cellular. Schewiakoff regards the lens as wholly 

 cellular, and like Glaus has not noted that internally this cell 

 structure may be quite obliterated. Schewiakoff regards the lens and 

 retina as formed from an invaginated sphere, and shows the 

 transition from the lens cells into retinal cells as I have figured. 

 Conant also gives the structure of the lens for the complex eyes as 

 cellular but missed the change of structure that the interior of the 

 lens may undergo. 



The Capsule. The capsule of the lens (Figs. 4, 7) lies immediately 

 below (inward from) the lens. In structure it is homogeneous, except 

 for certain fibers from the long pigment cells of the retina that 

 traverse it, while sometimes also other fibers can be seen which, 

 possibly, are branches from the fibers just mentioned or continuations 

 from the fine fibers of the prism cells of the retina soon to be 

 described. I have, however, no evidence that the fibers from the 

 prism cells extend beyond the prisms in whose axis they lie. The 

 capsule lies very closely applied to the lens, never becoming separated 

 from it in sections, and is, hence, regarded as a secretion from the 

 lens cells. Just what its function may be is difficult to surmise. 

 The proximal complex eye possesses no capsule. I have thought, 

 however, that if the lens should be adjustable, the capsule might 



