VII.] THE COMMON FROG. iii 



In the Urodela we also meet with a femoro-caudal, 

 but no such structure exists in the Anoura. This is 

 not so surprising when we recollect the abortive con- 

 dition of the tail of the Frog. It might, however, 

 have been expected that in the Tadpole, during the 

 co-existence of the tail with the hind legs, and while 

 it thus externally resembles an eft — such a muscle 

 would transitorily exist. Such, however, is not the 

 case, and the distinction is a very remarkable one. 



In one point, however, the Efts resemble the Frogs, 

 namely, in the greater number and greater complexity 

 as well as the greater size of the muscles of the hind- 

 limbs than of the fore-limbs. It is well known that 

 the Efts make use of their hind-limbs in attaching 

 their eggs to the leaves and branches of aquatic 

 plants ; and further observations may show with re- 

 gard to these animals facts, as to the use of the 

 members, as novel and interesting as the one just 

 cited with regard to the nest-building actions of the 

 Froe. 



