THIRD PERIOD. 121 



as a taste for the science becomes more generally 

 diffused, and the collections afford means of more 

 positive and varied instruction. 



M. Geoffroy de St. Hilaire resumed his lec- 

 tures at his return from Egypt, where he was 

 employed during four years. In his annual 

 course, after describing the animals by their ap- 

 parent characters, he presents zoology under a 

 general view, embracing and connecting all its 

 parts. This method reposes on four consider- 

 ations, which may be termed the four primor- 

 dial views of anatomical philosophy : viz. the 

 theory of analogies; the principle of connexions; 

 the balance of dimensions ; and the elective af- 

 finities of the organic elements. According to 

 this plan he no longer confines himself to the 

 description of external forms, but shews the 

 cause of these forms in the modifications of the 

 interior organisation ; thus seeking to link the 

 parts to the whole , and to present the science 

 under a larger aspect. 



M. Geoffroy had taught the history of all the 

 vertebrated animals for eighteen months, when 

 the law of the 7th of December 17947 at the 

 request of the professors, erected a separate chair 

 for oviparous quadrupeds, reptiles and fishes \ 

 to which M. de Lacepede, who had left the gar- 

 den two years before, was called in January 



