CHAPTEE 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 con- 

 sider 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 arrange- 

 ments of their organs, considered as so many inert parts ; and 

 though we may establish several wide conclusions respecting 

 the separate 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 



