190 
DR, F. SEMON AND MR. V. HORSLEY ON AN INVESTIGATION 
the clonic stage the cords execute movements synchronous with the twitcliings of the 
thoracico-abdominal respiratory muscles. 
Masini^ made in 1888 a series of both excitation and ablation experiments on the 
cortex of Dogs. In the former he found in four cases that excitation with weak 
currents produced earlier movements of the opposite vocal cord, followed by later and 
slower movements of the cord corresponding to the side of stimulation. He is the only 
experimenter, so far as we know, who has obtained such unilateral results. With 
stronger currents he obtained bilateral movements. According to his views the 
representation of the adductory movements of the vocal cords is spread over the 
whole motor area, though focussed in the centres for the soft palate and tongue. 
AronsohnI mentions in a paper, published in the same year, briefly, that in his 
experiments he could not obtain any definite reply to the question whether the 
adductory movements of the vocal cords observed by him were actually due to the 
stimulation of the brain. 
Mott,| in repeating our observations, corroborated our results. 
Two very important papers on the root-fibres of the motor nerves of the larynx, by 
Grossmann§ and Grabower|| respectively, we only desiie in this connection to 
menti<jn by title, as the subject of their researches rather refers to the peripheral part 
of the nervous mechanism of the larynx. 
The above short list comprises, so far as we know, all experimental contributions to 
this question, in which the intrinsic laryngeal movements have been actually observed 
or recorded, when the central nervous system has been stimulated. 
The clinical evidence concerning the relationship of the larynx to the higher nervous 
centres is also very limited. 
That lesions of the medulla oblongata may and do occasionally cause laryngeal 
paralysis, is, of course, admitted on all hands. In such cases it is, correctly speaking, 
I'ather a lesion of the vago-accessory nucleus and fibres in the medulla oblongata than 
a genuine central affection, to which the laryngeal paralysis must be attributed. 
With regard to the higher nervous centres, however (cortex and internal capsule), 
matters are very different. 
Although a certain number of cases have been published (c.p^., by Andral, 
Gerhardt, Friedreich, Foville, Duval, Lori, Lewin, Liyio Eonci, Luys, Cartaz, 
Massei, &C.I1), in which simultaneously with organic lesions of the higher centres 
* ‘ Archivi Italiani di Larjngologia,’ Napoli, April, 1888, p. 45. 
t “ Zur Pathologie der Glottiserweiteiaiiig,” ‘ Deutsche Med. Wocbenschr.,’ 1888. 
X ‘Brit. Med. Journal,’ 1890. 
§ “Ueber die Athembevveguugen der motorischen Kehlkopfnerveu, II. Theil,” ‘ Sitzuugsberichte 
der Kais. Akad. d. Wissenscli. zu Wien,’ November, 1889. 
II “Das Wurzelgebiet der motorischen Kehlkopfnerven,” ‘ Centralblatt fiir Physiologic,’ January 4,1890. 
^ The literature of these cases will be found in Masint’s, Garel and Dor’s, and in Rossbach’s papers 
hereafter referred to in the text. They are not quoted here at length, because these author.s themselves 
admit that they cannot claim to be of a decisive character for the question at issue. 
