276 



r. H. EDGE WORTH. 



to the long- forward projecting basihyal (Text-fig. 63), and 

 is attached to it near its anterior end. In larvae of Bufo, 

 Raua, and Pelobates the hyo-glossns is not attached to the 

 rudimentary basihyal. 



The development of the lingual muscles of La cert a 

 mural is has also been investigated by Kallius. The develop- 

 ment of the lingual muscles in other groups of Sauropsida 

 (loc. cit.) showed that the primitive condition of the lingual 

 muscles is a genio- and hyo-glossus, both developed from 



An.o{.cH.su{> nuuuL.hvy 



Rabbit, emiiryo 3^ mm., longitudinal vertical section. 



the genio-hyoid, attached to the long basihyal, the former 

 to its front end, the latter to its side ; and that extension 

 into the tongue is a secondary phenomenon. 



The condition of the hyo-glossus of Alytes is of interest 

 when considered in relation to that of the lingual muscles of 

 Sauropsida. Gegenbaur was of opinion that "^die Musku- 

 larisirung scheint vorwiegend im Dienste der Drusen zu 

 stehen." An alternative hypothesis suggested by the con- 

 dition in Alytes larvae would be that the condition in Saurop- 

 sida is the primary one, and that their functions as glandular 

 muscles in Amphibia is correlated with the absence (e.g. 



