The Amphibian larynx. 



299 



wirken bei ihrer Contraction genau in dem Sinne derselben (der 

 Pharyngealmuskeln) und sind çlaher im Stande, die Action der Pharynx- 

 muskeln direct zu unterstützen." 



The conclusion regarding this would vary very much in accor- 

 dance with the section taken and with the point regarded as the most 

 usual punctum fixum. Thus in Fig. B, taken through the wide 

 l)ortion of the cartilage, the ventral Laryngeus might admit of such 

 an interpretation provided it worked alone, but in Fig. C, cut lower 

 down it is hard to see how the action of Dorso-branchialiSs (= Dorso- 

 l)haryngeus) could have the same etfect as the Laryngei, pulling upon 

 the cartilage from the opposite side. Here the Puncta fixa are 

 plainly the median raphes and the dorsal origin of Dorso-branchialis 5 , 



Fig. c. 



Mb. Lg. r. 



Ventral {cardiac) 



D^ Lat Ltj.D. Lat Dorsal [^Pharyngeal) 



Section taken lower down in the same series as Fig. B. Mb. membrane completing- 

 the cartilage ; Z>j Dorso-branchialis 5 (here = Dorso-laryngeus) ; other letters as in the 

 preceding. 



and their action must be that of direct antagonists with regard to the 

 cartilage held in suspension between them. The Laryngei, by drawing 

 the cartilages towards the median line would tend to close the 

 respiratory aperture which the 5tii Dorso-branchialis would draw the 

 cartilages apart and serve to dilate the orifice. 



The view here set forth concerning the Laryngei appears to be 

 strengthened by the cross-sections of larval forms published by Göppebt 

 in the work so often quoted (.No. 6). If we refer to fig. 7 on p. 48 

 of this work, representing a cross-section through the larynx of a 

 larval Pleurodeles, we see the two Laryngei separated from the Dorso- 

 pharyngeus (D^) by a tendinous inscription, which, although referred 

 to by the same letter as the important rudiment found between J)^ 

 and Fg (= 4^h epibranchial) is here seen to be a different part. If, 



