Vlll PREFACE. 



The subject of Generation includes a consideration of the differ- 

 ent forms of Reproduction in the Animal Kingdom ; the Develop- 

 ment of the Vertebrate Embryo, its Appendages, Organs, and 

 Tissues, and mode of Reparation of the latter. The Evolution of 

 the Chick is taken as the groundwork of the Description of the 

 Embryo. 



This Volume concludes with brief Sections on the Growth of 

 the Body, its Decay and Death. 



In treating each Function, the Structure, and, where necessary, 

 the Chemical Composition and Physical Properties of the several 

 Organs, are described ; and care is taken to indicate the Mechani- 

 cal, Physical, and Chemical conditions, in harmony with, and fre- 

 quently by the co-operation of which they are performed. 



At the end of each Section, the General or Essential Characters 

 of a given Function, as distinguished from its Special Characters 

 in Man, are illustrated by copious references to the Structure and 

 Uses of the Organs concerned in that Function in the several 

 Classes of Animals. 



The Author desires here to express his deep obligation to Mr. 

 John Castaneda, for much valuable and prolonged assistance. 



10 SAVILE Kow, 



October, 1867 



