CHAPTER I. 



THE PROBLEMS OF MORPHOLOGY. 



175. THE division of Morphology from Physiology, is 

 one which may be tolerably-well preserved so long as we do 

 not carry our inquiries beyond the empirical generalizations 

 of their respective phenomena; but it is one which becomes 

 in great measure nominal, when the phenomena are to be 

 rationally interpreted. It would be possible, after analyzing 

 our Solar System, to set down certain general truths respect- 

 ing the sizes and distances of its primary and secondary 

 members, omitting all mention of their motions ; and it would 

 be possible to set down certain other general truths respect- 

 ing their motions, without specifying their dimensions or 

 positions, further than as greater or less, nearer or more re- 

 mote. But on seeking to account for these general truths, 

 arrived at by induction, we find ourselves obliged to consider 

 simultaneously the relative sizes and places of the masses, 

 and the relative amounts and directions of their motions. 

 Similarly with organisms. Though we may frame sundry 

 comprehensive propositions respecting the arrangements of 

 their organs, considered as so many inert parts; and though 

 we may establish several wide conclusions respecting the sepa- 

 rate and combined actions of their organs, without knowing 

 anything definite respecting the forms and positions of these 

 organs; yet we cannot reach such a rationale of the facts as 



