THE FUNCTIONS OF LIFE. 49 



particulars, but agreeing as to general characters. The same 

 observation applies to the families, the genera, and other 

 subordinate groups of living beings. 



The more extensive our acquaintance is with the anatomy 

 and physiology of both plants and animals, the more striking 

 do these analogies appear; so that amidst endless diversity 

 in the details of structures and of processes, the same general 

 purpose is usually accomplished by similar organs and in 

 similar modes. So firmly is this principle established, that 

 we may venture with confidence to predict many circum- 

 stances relating to an unknown animal, of which only a few 

 fragments are presented to us, from our general knowledge 

 of the characters and economy of the tribe or family, on the 

 type of which it has been modelled. Thus, the discovery 

 of a mutilated portion of the skeleton of a fossil animal, gives 

 to the physiologist, who is conversant with the details of 

 comparative anatomy, a knowledge of the general structure 

 and habits of that animal, though all other traces of its exist- 

 ence may have been swept away, amidst the primeval revo- 

 lutions of the globe.* 



Not only does this tendency to conform to particular types 

 obtain in all organic formations, but farther inquiry leads to 

 the conclusion that the deviations from these standard forms, 

 far from being arbitrary, are themselves referrible to par- 

 ticular laws. The regulating principle of the variations is 

 subordinate to higher views, and has reference to tlie respec- 

 tive objects and destination of each particular species in the 

 general system of created beings. Nature, as far as we can 

 discern, appears, in conformity with these intentions, first 

 to have laid down certain great plans of functions to which 

 she has adapted the structure of the organs; the minor ob- 

 jects and more subordinate functions being accommodated 

 to this general design. Hence arises the necessary and re- 

 ciprocal dependence of each organ and of each function on 



* See Cuvier's "Discours sur les Revolutions de la Surface du Globe,*' p. 

 47, prefixed to the first volume of lii;^ Osscmens Fossiies.'* 



Vol. I. 7 



