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doomed to a stationary existence, with 

 even less appearance of organization than 

 we usually discover in vegetables, and of 

 a structure so simple as to admit of pro- 

 pagation like vegetables by cuttings. 

 Yet in all the diversity of living beings 

 we recognize certain processes peculiar 

 and essential to life ; as the power of 

 converting other kinds of matter into 

 that appropriate to the individual it 

 is to form and support ; the power of dis- 

 tributing the nutriment, thus converted, 

 to every part for its formation and sup- 

 ply; the ventilation, as I may call it, 

 of the nutritive fluids; the power of 

 preparing various dissimilar substances 

 from the nutritive fluids; and the pro- 

 pagation of the species. As what is 

 deemed the complexity of animal life 

 increases, we find distinct organs allotted 

 for each of these functions ; thus we have 

 organs of digestion, circulation, respiration, 



