

GREAT STEPS IN EVOLUTION 71 



It may be that what we call " living " 

 evolved in Nature's laboratory from what 

 we call " not-living," for though prolonged 

 experiments have led biologists to adhere 

 dogmatically to the dictum "omne vivum e 

 vivo," this is not inconsistent with supposing 

 that spontaneous generation occurred in 

 favourable conditions very long ago. Verworn 

 has elaborated a suggestion due to the great 

 physiologist Pfliiger (1875), that the cyanogen 

 radical (CN) may have been the starting- 

 point of the proteid molecule which is the 

 essential part of the physical basis of life. 

 As cyanogen and its compounds arise in 

 an incandescent heat when the necessary 

 nitrogenous compounds are present, they may 

 have been formed while the earth was still 

 aglow; with their property of ready decom- 

 position they were forced into correlation 

 with various other compounds likewise due 

 to the great heat; when water was precipi- 

 tated upon the earth these compounds entered 

 into chemical relations with the water and 

 its dissolved salts and gases, and thus origin- 

 ated extremely labile, very simple, undiffer- 

 entiated living substance, which perhaps fed, 

 as Sir Ray Lankester has suggested, upon 

 " antecedent steps in its own evolution." 



It must be notedrliQwever, (1) that although 



