WORK UPON VISCERAL AND ALLIED NERVES. 67 



lumbar roots in the dog ; in the cat chiefly by the fourth 

 occasionally by the third and fifth, and in the rabbit by the 

 fourth and fifth, together with either the third or second 

 lumbar. 



These fibres pass, by the mesenteric nerves, from the 

 sympathetic chain to the inferior mesenteric ganglion, 

 thence by the hypogastrics to the bladder. Nerve cells in 

 their course can be shown by the nicotine method. They 

 are either situated in the inferior mesenteric o-ano-lion or 

 along the course of the hypogastrics. Stimulation of this 

 set causes a much weaker contraction than stimulation of 

 the sacral set, a contraction not sufficiently powerful to 

 cause micturition. The lower set of fibres occur, in the 

 rabbit, in the third and fourth sacral with a few in the 

 second, or in the second and third sacral with a few in the 

 fourth ; in the cat, in the second and third sacral, oc- 

 casionally in the first, and in the dog, in the second and 

 third sacral with sometimes a few in the first coccygeal. 

 Stimulation of these fibres causes micturition. They reach the 

 bladder vm the pelvic nerves and hypogastric plexus. Their 

 course is broken by nerve cells which occur scattered along 

 the course of the fibres usually near the viscus itself, e.g:, 

 in its lateral ligament. Inhibitory fibres were looked for 

 but without any positive result; they consider that if any be 

 present they are only few in number. Recently Courtade 

 and Guyon ^ have published results of experiments upon 

 this subject which, however, only confirm some of our pre- 

 vious knowledge. They are apparently unacquainted with 

 the papers of Sherrington, Griffiths, and Langley and 

 Anderson. 



In the frog Gaskell ' found two sets of fibres correspond- 

 ing to those in mammals. The lower set occur in the 

 eighth and ninth spinal nerve roots, and stimulation of 

 them caused marked contraction of the longitudinal coat. 

 The upper set are represented by fibres in the seventh 

 nerve, which he describes as causing contraction of the 



'^ Arch, de Phys., vol. xxviii., p. 622, 1896. 

 "^Joiini of Phys., vol. vii., p. 26, 1886. 



