will.\rd: cranial nerves of anolis carolinensis. 85 



By the same comparative method Fischer ('52, p. 49) estabhshed 

 the innervation of the cerato-hyoideus from IX and the laryngeal 

 muscles from X. For in two cases (Euprepes schac and Lacerta ocel- 

 lata) IX was found to be free from X, and in these cases its distri- 

 bution was to the cerato-hyoideus muscle and to the phar^Tix wall 

 anterior to the lar\Tix. Nerve X in these cases is a pure superior 

 laryngeal and goes to muscles and mucous surfaces of the larynx 

 (i. e. is of mixed nature, carrying both motor and sensory fibers). 

 This gives ground for the view that a like condition exists in those 

 forms where it cannot be actually demonstrated. 



Van Bemmelen ('89) considers Fischer's work open to criticism 

 in this particular connection because he did not establish the homol- 

 ogy of the rami by means of their relation to the aortic arches. Both 

 Van Bemmelen and, more recently, Goppert ('99) contradict Fischer's 

 conclusions regarding the sensory nature of ramus recurrens X. Gop- 

 pert, in an article which deals comparatively with the larynx region 

 in Amphibia and reptiles, concludes with this statement (p. 23): 

 "Bei alien Reptilien haben wir also Berechtigung zu der Annahme, 

 dass der Recurrens bis zum Kehlkopf gelangt, trotz des oft weiten, 

 von ihm zuriickzulegenden Weges. Dass er dann aber iiberall die 

 Kehlkopfmuskulatur ^■ersorgt, wird keinem Zweifel unterliegen 

 konnen, nachdem er sich fiir die Lactertilier direkt erweisen Hess." 

 These differences of opinion cannot be attributed to the study of 

 different reptiles, for Goppert makes use of the same genus (Platydac- 

 tylus) as that employed by Fischer. 



The present results in Anolis, then, do not clear away the uncer- 

 tainties of the general question of larynx innervation; they tend, 

 however, to suggest the probability that both the sujierior laryngeal 

 and the recurrent branch may carry motor fibers, these showing 

 different proportions in the rami of different forms. 



Q. SPINAL ACCESSORY NERVE. 



A spinal accessory nerve was not discovered in Anolis. In all the 

 described reptiles a portion of the vago-glossopharyngeal components 

 are grouped as nerve XI, or spinal accessory. Peripherally there are 

 generally two anatomical conditions which warrant this interpreta- 

 tion : (a) the caudad extension of the vagus series of roots beyond the 

 limits of the cranium, and (b) the distribution of a motor ramus from 

 the vagus (distal to the ganglion) to certain of the muscles of the 

 shoulder girdle. Both these features are absent in Anolis. 



