396 JAMES ROLLIN SLONAKER 



The annular pad is separated from the lens proper by a space 

 of variable thickness (fig. 28, Lc), the lenticular chamber, which 

 is filled with IjTiiph and granules arranged in clusters of indefi- 

 nite shape. The lenticular chamber, as seen in a section along 

 the axis of vision, resembles somewhat a comma in shape. Its 

 larger, globular part is near the posterior margin of the annular 

 pad. It narrows as it extends forward until it disappears at the 

 anterior margin of the pad. 



According to Henle ('79) and Ritter ('00) the lenticular cham- 

 ber plays an important part in accommodation in the bird. I 

 think its function is mainly if not wholly that of nourishment. 

 Development shows it to be the remains of the embryonic lens 

 cavity. Its location is at the line of junction of the inner sur- 

 face of the lens capsule. 



The corneal part of the annular pad is not very sharply sepa- 

 rated from the lens proper. The cells at the anterior margin 

 are short and radially arranged with the center of the lens as a 

 centre. The single row of nuclei is situated near the peri- 

 pheral ends of the cells. Toward the equator of the lens these 

 cells become gradually longer, six-sided prisms. Instead of 

 radiating directly from the center of the lens, they are more 

 and more bent, with the concave side forward (fig. 28, Ap). 

 The greatest curvature of these cells occurs at the thickest 

 portion of the annular pad or the equator of the lens. Toward 

 the posterior margin of this pad these cells become less and less 

 bent, until at the extreme posterior margin they are almost 

 straight and again radiate as before. 



The inner ends of the cells of the annular pad appear to be 

 globular. This is more pronounced from the equatorial region 

 to near the posterior margin or where the lenticular space is 

 widest. When these cells are examined with an oil-immersion 

 lens one is impressed by then- glandular appearance. The 

 material filling the lenticular chamber also appears to be a coagu- 

 lated secretion. The globular portion, which under low power 

 looks like the inner ends of the cells, is seen to be a granular mass 

 protruding from the end of the cell. The 'granules are not dis- 

 tributed uniformally throughout this mass, but there is a space 



