AND THE L0WEE ANIMALS. 103 



entirely new light, inasmuch as it tends at the same 

 time to elevate and degrade an animal in the zoological 

 series. Hereafter we shall find several examples of 

 this double action ; consequently, we shall see the 

 animal in its perfect condition, placed sometimes above, 

 and at others below its larval state, according as one 

 or other of these opposite tendencies has the upper 

 hand. 



