OF NUTRITION; OR, WHY WE GROW. 39 



by chemical change within it (its partial and regu- 

 lated decomposition), have been compared to the 

 motions of a clock, produced by the regulated gravi- 

 tation of its weights. The present question, there- 

 fore, would be, How are the weights raised ? 



It is evident that this question does not cover all 

 the ground that remains. It leaves on one side at 

 least two distinct subjects one the first origination 

 of Life ; the other, the FORMS which organic bodies 

 assume. Neither of these questions comes within 

 our present regard. Our inquiry is, how living 

 organisms grow and are nourished under existing 

 conditions ; and that only in one aspect of the case. 

 For the body not only increases in size and weight 

 from its first formation till maturity, but while this 

 process is going on it receives a certain shape. It is 

 not only nourished but organized. The various parts 

 are fitted to each other, and the whole presents, in 

 every order of creatures, a typical or specific form, 

 which is, indeed, one of the chief distinctions of the 

 organic world. But we do not here concern our- 

 selves with this curious fact. We ask only, by what 

 means new materials are added to the living body in 



