OPINIONS ON GENERAL PHYSIOLOGY 



159 



herself imitates her procedures in fecundation in 

 another state of things, without having need of the 

 union or of the products of any preexistent organiza- 

 tion." 



He proceeds to observe that in the places where 

 his aura vitalis, or subtle fluid, is very abundant, as 

 in hot climates or in heated periods, and especially in 

 humid places, life seems to originate and to multiply 

 itself everywhere and with a singular rapidity. 



" In this high temperature the higher animals and 

 mankind develop and mature more rapidly, and dis- 

 eases run their courses more swiftly ; while on the 

 other hand these conditions are more favorable to 

 the simpler forms of life, for the reason that in them 

 the orgasm and irritability are entirely dependent on 

 external influences, and all plants are in the same 

 case, because heat, moisture, and light complete the 

 conditions necessary to their existence. 



" Because heat is so advantageous to the simplest 

 animals, let us examine whether there is not occasion 

 for believing that it can itself form, with the con- 

 course of favorable circumstances, the first germs of 

 animal life. 



" Nature necessarily forms generations, spontaneous 

 or direct, at the extremity of each organic kingdom or 

 where the simplest organic bodies occur.'' 



This proposition, he allows, is so far removed from 

 the view generally held, that it will be for a long 

 time, and perhaps always, regarded as one of the 

 errors of the human mind. 



" I do not," he adds, " ask any one to accord it the 

 least confidence on my word alone. But as surely it 

 will happen, sooner or later, that men on the one 



