Vlll PREFACE. 



Believing, as he does, that such inferences are more satisfac- 

 torily based upon the general manifestations of Law and 

 Order, than upon individual instances of Design, he has 

 thought it the legitimate object of this treatise to lay the 

 foundation for them, by developing, so far as might be, the 

 Principles of Physiology, leaving it to special treatises on 

 Natural Theology, to build-up the applications. 



UNIVERSITY HALL, LONDON, 

 Jan. 1859. 



