428 Dr. F. Semon. On the Position of the 



to their antagonists, could, anatomically considered, be the stronger 

 ones, as supposed in Bosenbach's hypothesis. 



Secondly, the abductors and adductors of the vocal cords, though, 

 in a certain sense, obviously antagonistic to each other (in that they 

 serve the diametrically opposed functions of opening and closing the 

 glottis), yet are not in the same sense antagonists as the extensors 

 and flexors of a limb. In the case of the latter, the different groups 

 of muscles presiding over the movements of the part serve purposes 

 identical in nature and in physiological value ; in the case of the 

 laryngeal muscles, however, not only are the functions different in 

 physiological importance, but certainly also to some degree quite 

 independent of one another. Whilst it is undoubtedly true that no 

 phonatory effect can take place without respiratory movements at 

 the same time coming into play for phonation is a sort of modified 

 expiration yet the reverse of this does not hold good, respiration 

 being in no way necessarily connected with, phonation. There is, 

 therefore, no reason why, in the performance of a function which is 

 independent of that subserved by the antagonistic group of muscles, 

 the latter ought to come constantly into play. 



Bosenbach's comparison, therefore, of the laryngeal muscles with 

 those of the limbs cannot in this respect be admitted to be 

 unreservedly applicable. 



Thirdly, if both groups of muscles, the abductors and adductors, 

 were in reality constantly and simultaneously innervated during quiet 

 respiration, and if the abductors merely predominated, one would 

 naturally expect that, in cases of isolated paralysis of the glottis closers, 

 such as in functional aphonia, the glottis should appear much wider 

 in quiet respiration than when seen under ordinary circumstances. 

 For, under such circumstances, the respiratory tonic innervation of 

 the glottis openers would continue to the same degree, whilst the 

 antagonistic innervation of the glottis closers, which, according to 

 Bosenbach's theory, must previously have counterbalanced, to some 

 extent, their abducting force, was absent. Yet the glottis of per- 

 sons suffering from bilateral paralysis of the glottis closers during 

 quiet respiration is not at all wider open than that of normal 

 persons. This again speaks very forcibly against the hypothesis of 

 a simultaneous innervation of the adductors and abductors with 

 preponderance of the latter. 



Fourthly, the fact independently demonstrated by Bosenbach him- 

 self in the paper referred to and by me* in several publications, viz., 



* (a.) " Clinical remarks on the proclivity of the abductor fibres of the recurrent 

 laryngeal nerve to become affected sooner than the adductor fibres, or even exclu- 

 sively, in cases of undoubted central or peripheral in-jury or disease of the roots or 

 trunks of the pneumogastric, spinal accessory, or recurrent nerves " (' Archives of 

 Laryngology/ vol. 2, 1881, p. 203). 



