107 



are figured, and I have failed to find the structures 

 described in my sections, which agree with those of Ilesse. 

 Hyde describes the rod cells as being simply supporting, 

 and not visual sensory cells, and, further, that it is the 

 inner interstitial cells (which lie between the rod cells) 

 that are continuous with the axial fibril of the rods on 

 the one hand and the optic nerve on the other. The rods, 

 however, as above stated, are undoubtedly continuations 

 of the rod cells, and though Methylene blue may be 

 perfect for nerve fibrils, it cannot alter this fact, which 

 has been observed by all observers in teased preparations 

 and sections. Any continuations of the inner interstitial 

 cells penetrating the outer sieve membrane will lie, 

 therefore, between the rods, just as the former themselves 

 lie between the rod cells. 



In addition to the normal rod cells with their rods 

 which have been considered above, there is a peripheral 

 region in which rod cells are present which differ slightly 

 in structure from the others and do not bear rods at their 

 bases (fig. 29, R. C. j).) ; these were called Pseudoretino- 

 phorae by Patten. They are regarded by Hensen as 

 young rod cells, and Schreiner states that he found them 

 to be more numerous in young specimens than in the 

 adult. 



So far we have only considered the rod cells and the 

 rods. In addition to these, the retina is made up of a 

 number of other cells which form a definite band between 

 the rod cells and the septum, and another layer, previously 

 mentioned (inner interstitial cells), which lie between the 

 rod cells. Patten classified all those between the septum 

 and the rod cell layer as belonging to the outer ganglionic 

 layer, and the others to the inner ganglionic layer. 

 Eawitz also classified all these cells together as ganglion 

 cells, and later Schreiner describes the outer ganglionic 



