288 On the Connection of Nerves and Chromohlasts. 



however, regard as rigorous, so long as it will not have been drawn 

 from embryogenic study. 



In Fig. 3 c, we have evidently to deal with a nervous thread, 

 characterized by the presence of a nucleus. We must remember 

 that there is not a trace of laminous fibres in all this tissue. This 

 nervous fibre appeared to us to continue directly with a pale chro- 

 moblast having numerous ramifications. The union seems to be 

 proved by some granulations scattered over the nervous thread near 

 the chromoblast. Fig. 3 / shows a similar arrangement, although 

 less clearly. 



The same arrangement is seen also in Fig. 2 and Fig. 3 h. 

 There, however, the filaments which appear really to continue with 

 the chromoblast, were not, so far as they were visible, provided with 

 nuclei. The same may be said of Fig. 3 e, which is certainly the 

 most characteristic of all those that we have observed. The 

 chromoblast was large, and very much retracted on itself like a 

 sphere. From the edge of the chromoblast was seen to extend a 

 thin filament, which could be traced pretty far, and which it was 

 hard to avoid considering as a nervous thread, although it pre- 

 sented no characteristic nuclei. But it ofiered, on the other hand, 

 certain interesting peculiarities near the outside of the chromoblast, 

 inside which the latter 's opacity of course prevented the pursuit. 

 This thread ofi'ered in this place strongly-marked sinuosities, which 

 are not usual on the course of the nervous fibres. But, besides, 

 we discovered easily on those sinuosities pigmentary granulations 

 analogous to those contained in the sarcodic substance. Error was 

 impossible. Beyond the first sinuosity especially were seen two of 

 those granulations, isolated and perfectly recognizable. Those 

 sinuosities, those granulations, appeared really to indicate that the 

 fibre there approaches its termination, enveloped in the sarcodic 

 substance when the latter displays itself. There exists there, then, 

 intimate contact, if not continuity of substance between the nervous 

 fibre and the chromoblast. 



One difiiculty indeed appears. The influence of the nervous 

 element on the contractile element is unquestionable, but it in no 

 way indicates what may be the relations or the connections between 

 the two elements. Does the nervous fibre become lost in the midst 

 of the contractile substance on coming into contact with the nucleus 

 of the chromoblast ? This is a first hypothesis, which we confess 

 appears to us highly probable, but which has not been demonstrated. 

 Influence exerted at a distance from the chromoblast by adjacent 

 nervous elements appears improbable, and besides, in opposition to 

 what we know to exist in the other parts of the organism. There 

 remains a third hypothesis : that the chromohlasts are merely 

 arranged on the course of a nervous element, and in contact with 

 it, and that only through the efiect of this contact they enter into 



