202 
DR. F. SEMON AND MR. V. HORSLEY ON AN INVESTIGATION 
tion went on unliinderecl. On the other hand, when closure of the glottis was evoked, 
the respirations wei'e distinctly slowed. 
We cannot pass from this part of the subject without adverting to tire remarkable 
way in which tlie laryngeal apparatus of the Cat is, as we have before remarked, 
extremely sensitive to the operation of the anaesthetic. Especially was this the case 
in making these experiments upon the cortex, since we found that a moderately deep 
narcotisation was sufficient to change the effect observed from adduction to abduction. 
The discussion of this we resume further on. 
Epilepsij .—We have occasionally observed epilepsy, and when it occurred the vocal 
cords were preliminarily brought together, and then moved in clonic adductory 
spasms. We would now like to state that it is the phonatory—or, as we may say, 
the purposive—adductory representation of tlie laryngeal movements which is inva¬ 
riably brought out in the epileptic discharge of the cortex; another proof, if proof be 
required, of our position that adduction is a movement characteristic of the highest 
cortical evolution as far as the larynx is concerned. 
Rodents. — Rahbit. 
Cortical representation of movement in the Ilabblt is, of course, well known to be 
very limited indeed, both in extent and in degree, the cortical centres being soon 
exhausted and the effects produced being relatively insignificant. We therefore only 
made two experiments upon this animal. We obtained no focal representation of the 
larynx, but the intrinsic movement observed concurrently with the movements of 
other parts were, as a rule, adduction; and, where this was most marked, the 
concomitant movement was that of swallowing. 
Corona radiata. 
We have, in a certain number of experiments, removed the cortex and excited 
the fibres beneath. As might be expected, our results all point to one conclusion, 
viz., that excitation of the fibres which lead in a direct line from the particular 
part of the cortex removed to the internal ca|)sule gives the same effects as did 
the cortex when that was excited. Thus, in the Dog we have observed that the 
white fibres leading down from the praecrucial gyrus gave acceleration and those from 
the isthmus of that gyrus adduction, whereas the fibres coming from the lower end of 
the postcrucial gyrus gave intensification of the respiratory movements of the vocal 
cords. Exactly the same is observed in the Cat, viz., that acceleration is coupled 
with adduction, and that, on excitation of the fibres coming from the abductor focus, 
we have as distinctly abduction. 
In no case, in accordance with the previous observations of various authors, did we 
obtain epileptic movements of the laryngeal muscles, after the cortex had been 
excised, l)y stimulation of the fibres leading therefrom. 
