■ CHAPTER VII. 



GENERATION IN BRUTE BODIES AND LIVING 

 BODIES. SPONTANEOUS GENERATION. 



Protoplasm a substance which continues — Case of the crystal — 

 Characteristics of generation in the living being — Property 

 of growth — Supposed to be confined to the living being — 

 Fertilization of micro-organisms— Fertilization of crystals — 

 Sterilization of crystalline and living media — Spontaneous 

 generation of crystals — Metastable and labile zones — 

 Glycerine crystals — Possible extinction of a crystalline 

 species — Conclusion. 



We have not yet exhausted the analogies between a 

 crystal and the living being. The possession of a 

 specific form, the tendency to re-establish it by re- 

 disintegration and the existence of a kind of nutrition 

 are not sufficient to constitute complete similarity. 

 It still lacks a fundamental character, that of genera- 

 tion. Chauffard some time ago, in an attack which 

 he made upon the physiological ideas of his day, 

 aptly exhibited this weak point. " Let us disregard," 

 he said, "those interesting facts relative to the acquisi- 

 tion of a typical form — facts that are common to the 

 mineral world as well as to living beings. It is none 

 the less true that the crystalline type is in no wa}- 

 derived from other pre-existing types, and that 

 nothing in crystallization recalls the actions ot 

 ascendants and the laws of heredity." 



This gap has since been filled. Th^ work of 

 294 



