NERVES OF MAMMALIA. 



183 



Section of sixth intercostal with communicating branch to 

 sympathetic. Rabbit (mag. 60 diam.). LXXVII-. 



A 



139 



to the coccyx : anteriorly, or above, they pass to ganglions and 

 plexuses, within, or 



about, the cranial -,& 



7 



cavity ; below or 

 behind, they con- 

 verge and unite, 

 generally, in a ter- 

 minal f coccygeal 

 ganglion. In their 

 course the cords 

 cross, ventrally, the 

 issuing trunks of 

 the spinal nerves, 

 with which they are 

 connected by short 

 threads, including 

 grey and white fila- 

 ments, and there 

 usually swelling into ganglions. The grey or gelatinous thread 

 is most probably a contribution from the ganglion to the myelonal 

 nerve, the white thread is sent 

 from the nerve to the sympa- 

 thetic ganglion : it consists of 

 tubular nerve-fibres, and these 

 predominate in the ' rami 

 communicantes ' of the rabbit 

 and cat. 2 Under a power of 

 sixty diam. after addition of 

 dilute solution of soda Drum- 

 mond found such fibres con- 

 tinued mainly from the mye- 

 lonal end or origin, fig. 138, 

 C, of an intercostal nerve, and 

 converging to form the com- 

 municating branch, RC, with 

 the sympathetic ganglion. A 

 few filaments, , , disappear 

 among those of the intercostal 

 nerve rather in the direction 

 of its outward course. Traced 



tO the Sympathetic gailgllOn, Fourth thoracic ganglion, with course of fibres received 



,1 I by the communicating branch, c, from the myelou. 



iiiey diverge, (Mag 70 diain.) 



1 Lxxvii". p. 446. 



B 



in fio- 



ng. 





