112 SEVENTH REPORT—1837. 
ture became completely closed, in the same manner as when the su- 
perior laryngeal nerves were uninjured. It must be at once obvious, 
that these experiments are completely subversive of the statement that 
the inferior laryngeal supplies those muscles only which open the glottis, 
while the superior laryngeal nerves furnish the motor filaments to those 
muscles which shut the glottis; they also illustrate, in a very satisfac- 
tory manner, the cause of the dyspncea in some cases where the inferior 
laryngeal nerves are cut or compressed. 
Dr. Reid has also satisfied himself, that when any irritation is ap- 
plied to the mucous membrane of the larynx in the natural state, that 
this does not excite the contraction of these muscles by acting directly 
upon them through the mucous membrane, but that this contraction 
takes place by a reflex action, in the performance of which the supe- 
rior laryngeal nerve is the sensitive, and the inferior laryngeal is the 
motor nerve. He has. also satisfied himself that the muscular contrac- 
tions of the cesophagus are not called into action by the ingesta acting 
directly as an excitant upon the muscular fibre through the mucous 
membrane, but by a reflex action, part of the cesophageal filaments 
acting as sensitive, and others as motor nerves. 
Spinal Accessory—In seven dogs this nerve was cut on one side, 
without affecting the ordinary voluntary movements of that side of the 
neck. In several animals a weak dose of prussic acid was given after 
the nerve had been cut on one side. In several cases this was followed 
by prolonged, forcible, and regular respiratory movements, after the 
animal had been deprived of all consciousness and voluntary motion. 
In three of these cases distinct movements of contraction and relaxa- 
tion were observed in the exposed sterno-mastoid muscles, synchronous 
with the other muscles of respiration. The contractions were perhaps 
weaker on the side on which the spinal accessory had been cut. 
Observations on the Structure of the Sacrum in Man and some of the 
Lower Animals. By Hucu Caruirzt, M_B.T.C.D. 
Mr. Carlile exhibited to the Section several anatomical prepara- 
tions of the human sacrum in different states of growth, in which the 
separate formation of the lateral parts, consisting both of ribs and of 
transverse processes, was distinctly shown. The analogous structures 
in certain of the Saurian and Chelonian reptiles were exhibited by 
means of preparations and drawings ; andthe errors of descriptive ana- 
tomists on these subjects were pointed out. Mr. Carlile showed that 
some of the Saurian reptiles afford the best examples of distinct and 
well-developed sacral ribs, although this peculiarity in their structure 
has wholly escaped the observation of previous anatomists. In these 
animals the sacral ribs are two in number on each side; the anterior 
being articulated to the bodies of the last dorsal and the first sacral 
vertebrae, and connected to their inter-vertebral substance—the poste- 
rior to the last sacral and first caudal vertebree. In the human sub- 
