518 



F. H. EDGEWORTIT. 



differences in certain muscles of the head which will be 

 described later on. 



Parker, who did not investigate any embryonic stages, 



inf ' flext 

 Rmf 



; , I g s 



\ quad & me an. 



Rsuf. 



R ext 



pirk 



nand my. 



cfuad i r^e an 



Text-figs. 10 and 11. — Sagittal sections througli an embryo of 

 Gallus at the end of the fifth day. 10 is the more external. (For 

 exphvnation of lettering see p. 555.) 



described the columella of the adult Chamasleon as consisting 

 of stapedial, mediostapedial, extrastapedial, and supra- 



