AND THE LOWER ANIMALS. 9 



selected the metamorphoses as the text of his dis- 

 course to the College of France. Dividing the entire 

 life of every animal into five distinct periods, he 

 examined the species themselves, and the groups 

 containing them, in these five periods, under the triple 

 point of view of external form, internal organization, 

 and performance of function. Four years hardly 

 sufficed to complete this huge scheme, doubtless the 

 best one calculated to give a complete notion of the 

 animal kingdom. It would certainly be required now- 

 adays. Since that time Science has enrolled many 

 new facts, and the doctrines of twenty years ago have 

 been very much modified. But I desire to recall here 

 the part taken in this scientific movement by him who 

 was my first master in Zoology, and my constant friend. 

 The germs or first rudiments of organized beings 

 may be referred to three principal and distinct types^ 

 which are found in both kingdoms.* Animals espe- 

 cially multiply by eggs, or by free or attached buds. 

 Further on we shall see more of these two modes of 

 reproduction. Let us state here, that the first form 

 alone is fundamental, and that the distinction between 

 oviparous and viviparous animals, although still al- 

 lowed in scientific parlance, is in reality only an appa- 

 rent one. Baer, in discovering the mammalian egg, and 

 M. Coste in discovering that it possessed the same 

 features as the egg of birds, have established this 



revised the proofs of a most important work upon the group of 

 man-like apes, and especially upon the Gorilla. M. Duvernoy died 

 in 1855. 



* I have discussed this question of germs at some length in the 

 " Souvenirs d'un Naturaliste," in the chapter headed " Saint- 

 Sebastian." 



