xiii 
actions in the other legs, and all the usnal signs of discomfort, 
excepting indeed in the leg itself. Thus then the excitability was 
destroyed, though the sensibility was unaffected. After awhile, how- 
ever, the former gradually returned. 
M. Faivre was also able to effect the converse operation—i. e., to 
destroy the sensibility without affecting the power of motion. To do 
this it was necessary to cut the inferior side of the ganglion, and espe- 
cially to avoid going deep. In this case, as in the preceding, action 
on the right side of the ganglion affected the right les, that on the 
left side the left one. Under these circumstances if the paralyzed 
leg is pinched no movements are produced either in it or in any other 
parts of the body; while, on the contrary, the paralyzed leg does 
move in the same manner as the others, under the stimulus of irrita- 
tion applied to any other part of the body. Thus then if a superior 
longitudinal section be effected through the side of the ganglion, the 
leg is rendered motionless, but other parts can be stimulated through 
it. On the contrary, if an inferior longitudinal section be made, the 
leg can be moved by stimulus applied elsewhere, but is rendered 
incapable of transmitting sensation. 
There is yet another manner in which the ganglion may be treated. 
If a lateral longitudinal section be carried through each side, the 
corresponding legs are completely paralyzed ; and yet, the conducting 
properties of the ganglion being unaffected, irritation of the antenne 
produces evident movements of the posterior feet, and, vice versa, irri- 
tation of the posterior legs produces movements in the head. 
M. Faivre has made several experiments on other portions of the 
nervous system. The supra-csophageal ganglion he finds to be quite 
without sensation. It may be pinched, pricked or torn, without any 
pain being manifested, thus presenting a remarkable contrast with 
other ganglia, and a not less remarkable analogy with the cerebral 
hemispheres of the, so-called, higher animals. It is curious that the 
commissures appear to gain sensibility as they quit the brain and 
approach the first subesophageal ganglion. 
The subcesophageal and other ganglia, so far as they have been 
examined by M. Faivre, present the same phenomena as the pro- 
thoracic; that is to say, they are motor above and sensory below; 
and an injury affects always the corresponding side of the body. 
He found the mesothoracic gauglion the easiest of all to examine, it 
being necessary for the purpose to remove only the membrane which 
unites the ventral surface of the prothorax with the mesothorax. 
