46 



EVOLUTION AND ANIMAL LIFE 



already indicated that the production of such compounds would 

 not necessarily be the production of protoplasm. What of the 

 complex definitive physical organization of protoplasm on 

 which we predicate so much of its capacity? 



The botanist Schaffhausen believes that water, air, and the 

 necessary mineral substances have been directly combined under 

 the influences of life and heat and have given birth to an 



FIG. 37. Opossum, Didelphys virginiana. (One-tenth natural size; photograph by 



W. K. Fisher.) 



uncolored protococcus which next became Protococcus viridis. 

 Delage asks: " If the thing is so simple why does not the author 

 produce one of these protococci in his laboratory? On lid ferait 

 grace de la chlorophylle ! " Nageli holds that when the albumi- 

 nous compounds had their birth in an aqueous liquid, as they 

 were not soluble in water, they were precipitated. This pre- 

 cipitate was formed of minute particles, a sort of crystal which 

 he calls micellae. These micellae are the materials from which 

 organisms were formed. An inorganic crystal deposited in a 

 saturated solution of the same nature determines a deposit 

 on its surface in the form of tiny crystals, by which means it 



