GROWTH AND NUTRITION. 87 



New views concerning the vital processes of Growth and 

 Nutrition* The act of nutrition is peculiar to living beings 

 and involves much more than the mere addition of new 

 particles to a definite portion of matter, as some have held. 

 Growth resulting from nutrition is so very different in its 

 essential nature from every kind of increase resulting from 

 deposition or aggregation, that it seems wrong to apply the 

 word "growth " to the process of increase in the two cases. 

 If the term is to be employed at all, with reference to living 

 things, it should be restricted to them entirely, for a stone 

 does not grow in the sense a living thing grows. Here, 

 however, at the outset, I find myself distinctly at issue with 

 one whose opinions on such questions are entitled to respect. 

 At the same time I cannot help feeling that if the author in 

 question had observed more for himself, and trusted less to 

 the arbitrary dicta and inconclusive statements of others 

 upon elementary questions of the highest importance, which, 

 as he well knows, have been very imperfectly worked out, 

 he would have been led to adopt conclusions at variance 

 with the doctrines to which he has, I venture to think, 

 prematurely committed himself. After affirming that the 

 increase in size of the plant, like the crystal, is effected by 

 continuously integrating surrounding like elements with 

 itself, Mr. Herbert Spencer saysf that the food of an 

 animal is " a portion of the environing matter that contains 

 some compound atoms like some of the compound atoms 

 constituting its tissues." If such be so, the peculiar sub- 



* The observations under this head formed the subject of a paper 

 published in the Trans. Mic. Soc., 1867. 



t "The Principles of Biology," vol. i. p. 108. 



