102 GRADATION AMONG ANIMALS. 



lectual one ? These correspondences are corre- 

 spondences of thought, of a thought that is 

 always the same, whether it is expressed in the 

 history of the type through all time, or in the life 

 of the individuals that represent the type at the 

 present moment, or in the growth of the germ of 

 every being born into that type to-day. In other 

 words, the same thought that spans the whole 

 succession of geological ages controls the struct- 

 ural relations of all living beings as well as their 

 distribution over the surface of the earth, and is 

 repeated within the narrow compass of the small- 

 est egg in which any being begins its growth. 



