122 LAKES AND RIVERS. 



either leap upon the ground or swim in the water. 

 The spinal column of the frog is extremely short, con- 

 sisting of " eight vertebrae, exclusive of those which 

 have united to form the os coccygis. It was evidently 

 the design of the Creator to consolidate the frame- 

 work of the trunk, in which flexibility was not required 

 for progressive motion, the performance of that func- 

 tion being transferred to the hind extremities, which 

 are exceedingly large in proportion to the rest of the 

 body. In every part of the skeleton there is a ten- 



THE DEVELOPMENT OF THE FROG. 



dency to develop itself in a transverse direction, 

 while the trunk is shortened as much as possible. 

 The mode in which the vertebrae are articulated 

 together approaches that of the higher animals." 



Dutrochet found, by careful study of the spawn 

 and formation of the cartilage first, and then from 

 the formation of the bones, that before the cartila- 

 ginous coccygeal vertebrae had ossified, the tail dis- 

 appeared; "the vertebrae nearest the body became 

 consolidated, and being joined to the sacrum at an 



