Ylll PREFACE. 



analogy. Discussions of this kind have been carefully 

 avoided in the following pages : to collect from every 

 available source the ascertained facts connected with 

 anatomical structure, and to arrange the grand divisions 

 of the animal world in conformity with progressive de- 

 velopement as we advance from humbler to more com- 

 plex types of organization, has been the chief aim of the 

 Author; and, if he has at all succeeded in divesting so 

 important a subject of those technicalities which not un- 

 frequently impede the progress of the general reader, 

 his labour has not been thrown away. 



To the Physiologist little apology is necessary for the 

 production of a work intended to exhibit at one view the 

 leading facts of Comparative Anatomy. In this country, 

 unfortunately, so extended a view of Nature is considered 

 as being by no means essential to a correct intelligence 

 of the laws of animal life, and as a branch of professional 

 education has been hitherto completely neglected. Our 

 illustrious countryman John Hunter entertained a dif- 

 ferent opinion. May the fire which he first kindled 

 amongst us, and which has since his time been kept alive 

 by the fostering care of that College, the depository of 

 his invaluable works, soon burst forth, and irradiate the 

 realms of science as brightly as the great founder of 

 Comparative Physiology foresaw that it might ! 



