CHAPTER VI. 



NUTRITION IN THE LIVING BEING AND IN THE 

 CRYSTAL. 



Assimilation and growth in the crystal. — Methods of growth 

 in the crystal and in the living being ; intussusception ; 

 apposition. — Secondary and unimportant character of the 

 process of intussusception. 



I HAVE already stated (Chap. VI. p. 209) that nutrition 

 may be considered as the most characteristic and 

 essential property of living beings. Such beings arc 

 in a state of continual exchange with the surrounding 

 medium. They assimilate and dissimilate. By as- 

 similation the substance of their being increases at 

 the expense of the surrounding alimentary material, 

 which is rendered similar to that of the being itself 



Assimilation mid Growth in the Crystal. — There 

 exists in the crystal a property analogous to nutrition, 

 a kind of nutrility, which is the rudiment of this 

 fundamental property of living beings. The develop- 

 ment of a crystal starts from a primitive nucleus, the 

 germ of the crystalline individual that we will 

 presently compare to the ovum or embryo of a plant 

 or an animal. Placed in a suitable culture-medium — 

 i.e., in a solution of the substance — this germ 

 develops. It assimilates the matter in solution, 

 incorporates the particles of it, and increases, pre- 

 serving at the same time its form, reproducing its 



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