354 H. M. BERNARD. 



tliey belong to the retinal protomitomic system, one would 

 expect tliem to be in the line between the nerve-layer and the 

 rods. But there is no reason why there should not be in any 

 organ subsidiary systems regulating vegetative processes 

 within the organ^ and apart from the specific functions of the 

 organ itself. 



Summary of the Leading Morphological and 

 Physiological Characters of the Protomitomic 

 System, as above described, in the Retina. 



The morphology of the retinal protomitomic system has 

 already been summarised in the diagram fig. 22. It is a 

 continuous reticulum of nearly invisible fibrils, which become 

 visible when coated with other matters. I have hesitated to 

 call them linin filaments because, as I shall show elsewhere, 

 that term is at present applied to substances quite distinct 

 from these filaments. But it is undonl)tedly the proper 

 application of the word. It underlies the Avhole retina ; the 

 nuclei are its nodes. Each node is a still closer reticulum in 

 which chromatin accumulates, and witli the chromatin a 

 quantity of clear fluid — nucleoplasm — which turns tlie node 

 into a turgid vesicle. This chromatin, massed on the fibrils 

 of the nodes, renders the latter not only visible but con- 

 spicuous objects. Distally, the filaments of the retinal proto- 

 mitomic system run out as a fringe, not of free threads like 

 cilia, but gathered into groups by supporting vesicles, the 

 rods. Proximally, the filaments are gathered as the " Neuro- 

 primitivfibrillen '^ into the nerve-strands wliich connect the 

 retina with the brain. 



The physiological characters of the protomitomic system, 

 as gathered from our study of the retina, have still to be 

 summarised. 



1. Since the protomitomic reticulum connects the optic 

 nerve with the fibrillation of the rods, its component filaments 

 are nervous. 



2. Since the intra-nodal reticulum soonis toliavotlio power 



