Nerves to the Skin of the Frog. 
29 
nard"^ with the following results — that the section of the fifth 
nerve, very near its origin_, produces sensitive and muscular 
paralysis,, but when it is divided beyond the gasserian gan- 
glion or on the ganglion itself^ then the division of the nerve 
is followed by remarkable signs of impaired nutrition. 
In confirmation of these results of experiment, Bernard 
records the case of a patient observed by him at La Salpe- 
triere, who was labouring under paralysis of the fifth nerve, 
accompanied by great disorder of nutrition and almost 
complete destruction of the corresponding eyeball. The pa- 
tient died, and at the post-mortem examination was found a 
tumour, which had not only compressed, but nearly destroyed 
the gasserian ganglion. 
Respecting the office of the ganglia in connection with the 
posterior roots of the spinal nerves, there are the results of 
Waller's experiments, which throw a ncAV light on this diffi- 
cult point. This physiologist first made known the strildng 
fact, that when both the roots of a spinal nerve are divided, 
namely, the posterior between the ganglion and the cord and 
the anterior before its union with the posterior, it is always 
found that that part of the posterior root, which remains in 
connection with the ganglion does not undergo any alteration 
whatever, while the other part of the spinal root connected 
with the cord is remarkably altered. A similar alteration 
takes place in the anterior spinal root, but invertedly. Hence 
Waller believes himself justified in drawing the conclusion 
that The ganglion governs the nutrition of the sensitive and 
the cord of the motor nerve-fibres. 
Bernard has repeated Waller's experiments with precisely 
the same results ; but he thinks that the only conclusion 
which may be safely drawn from Waller's and his own expe- 
riments is, that the spinal cord conserves the anterior and the 
ganglion the posterior root, or, in other words, the ganglion 
plays the same part in the nutrition of sensitive fibres as the 
cord in tliat of the motor ones. It must also be added that in 
all experiments of Bernard no remarkable signs of impaired 
nutrition followed the section of the posterior roots of the 
spinal nerves. t 
Although Bernard's experiments seem to prove that we 
must assign to the spinal ganglia an office diff*erent from that 
of the gasserian ganglion, yet it may be justly objected that 
in all his experiments, except one, were only divided the pos- 
* * Le9on5 sur la Physiologie et la Pathologic du Systeme nerveux," 
vol. ii, p. 49. Paris, 1858. 
f 'Meme Ouvrage.' " Treizieme Le9on," p. 233, vol. i. 
