54 



BRISTOL. 



[Vol. XV. 



Anl . 



ViSPC. 



IJUNCTW*/ 



Text-fig. 3. — A very narrow 

 tangential section showing the 

 long bipolar cells running from 

 junction to junction through 

 two metameres and five rings. 

 (Camera drawing from a gold 

 cliloride preparation.) 



those central endings which enter by 

 the anterior nerve. I have not been 

 able to determine which of the dorsal 

 cells send in fibers by way of the pos- 

 terior nerve. The ring itself, as shown 

 in the gold-chloride preparations, con- 

 sists of numerous fine fibers, which 

 come in part from the bipolar cells, in 

 part from the central system, and in 

 part from the diffuse sensillae in the 

 epidermis. It gives off fibrillae which, 

 ramifying the bundles of long muscles, 

 innervate the cells. 



As I have said above, these rings 

 are connected, one with another, by 

 long bipolar cells lying between the 

 same muscle layers, as shown in PL V. 

 These connecting cells form, when taken 

 together, eight longitudinal paths, reach- 

 ing, according to my present investiga- 

 tions, from metamere VII through the 

 body region to metamere XXV. I 

 have no doubt that they may be found 

 in the regions of the terminal somites, 

 but I have not yet been able to do so. 



These long connective cells join the 

 nerve rings at the points where the 

 branches from the central system come 

 into the ring (Fig. 3 in the text). 

 Every point of connection of the ring 

 with the central system is also a point 

 of junction with two long bipolar cells. 

 I regret exceedingly that the histologi- 

 cal character of this junction is wholly 

 obscured by the swelling of the tissues 

 by the formic acid, and I hope to study 

 this detail by the use of Golgi's method 

 of silver impregnation or methylen 



