324 H. M. BEENAIU). 



Having found, then, that the fihiments of tlie i*etinal pro- 

 tomitomic system are proximally continuations oi: the nevve- 

 fibrils, we have now to ascertain how, distaliy, this system is 

 associated with the rods. 



In Part II (page 447) I rioted that Max Schultze, who was 

 one of the first to discover threads or parts of them running 

 down the rods, had clearly desired to regard them as tlie 

 nerves. He reluctantly felt obliged to abandon that view 

 because the threads seemed to lose themseh^es in the '' con- 

 nective tissue" of the outer layers of the retina. We are 

 now in a position to clear up this difficulty. There can be no 

 doubt that Max Schultze saw our nuclear filaments striating 

 the inner limb of the rod. But he failed to trace them back 

 into the intra-nuclear network of the rod-nucleus. Such an 

 origin one would have thought must have been actually 

 suggested to him by the observations connecting nerves and 

 nuclei above referred to, especially as this would have served 

 to link the strife on the rods with the rod- and cone-fibres, 

 in which he thought he saw, and in some instances I believe 

 correctly, bundles of primitive nerve-fibrilloe. But, in his 

 endeavour actually to see whence the stria) came, he was led 

 astray by certain root-like streaks where the rods join the 

 retina, and which often look like fibrils, but are, in reality, 

 the streams of pigmentary matter absorbed by the rods and 

 finding their way round their bases into the syncytial reti- 

 culum of the retina. This is evident fi-om his statement that 

 the fibrils run into the connective tissue ; for here they join 

 together to form the " Miiller's fibres" (cf. Part V, PL V, 

 figs. 25 n — c).i While admitting that it might be difficult to 

 find any single preparation showing the whole of the details 

 at a glance, it is none the less clear, from the facts described 

 in these studies, that we must distinguish between these two 

 systems of stri;y. On the one hand, as Ave shall presently 

 show, we have nuclear fibrils which are nothing less than the 



' Boiysiekiewilz was also led astray by these, and concluded t.iiat the 

 Miiller's Qbres must convey the nerves; see my remarks ou this theory in 

 Part V, p. 66. 



