210 THE NATURE AND ORIGIN OF LIFE 



by the little knowledge of the exact sciences generally 

 possessed by professional biologists. On the contrary, 

 explanations based on equilibrium are very satisfying when 

 we study the adaptive evolution of living species. A few 

 pages will show this presently ; but we must first occupy 

 ourselves with a question that complicates in most cases 

 that of heredity so-called. I mean the sexual phenomena so 

 widespread in the animal and vegetable kingdoms. 



