No. 643] 



ORTHOGENESIS IN BACTERIA 



113 



autotrophic bacteria and, second, the possibility and even 

 probability that sufficient amounts of organic matter for 

 ba^iterial purposes may have been elaborated at the dawn 

 of life by chemical means, using the term chemical " 

 in the broadest sense. It is, of course, well known that 

 the autotrophic bacteria, for example, the nitrifying bac- 

 teria, can live and build organic matter out of purely 

 inorganic substances, carbon being obtained from carbon 

 dioxide of the air, and in the absence of light and chloro- 

 phyll. But if this is so, why may it not be that of the 

 known forms of living cells, the autotrophic bacteria 

 were the first, since they are capable of living in a purely 

 inorganic medium, the ammonia which is necessary to 

 them being supplied from the small amounts resulting 

 from chemical reactions induced by electrical phenomena 

 in the atmosphere. As we have seen thus far, it may be 

 argued, with equal justice, that the activity of the nitri- 

 fying bacteria is a highly specialized one on the one 

 hand, and a very primitive one on the other. 



But if, as just indicated, it should be argued that, after 

 all, the autotrophic bacteria are exceptions in the bac- 

 terial world and that most bacteria need elaborated or- 

 ganic matter and hence they could not have been the 

 primordial living cells, the second objection which I have 

 stated may be urged, namely, that organic matter may 

 have existed on the earth before living cells came into 

 being. Mature reflection will render it highly plausible 

 with the high temperatures, great electrical activity, 

 and probable intense radioactivity wliich existed on the 

 planet prior to the appearance of living cells, that un- 

 usual chemical activity inducing rapid and general com- 

 binations among the elements should have prevailed. 

 This, moreover, involves the assumption of the existence 

 of a degree of all these conditions which is requisite for 

 the synthesis, but not for the rapid destruction of the or- 

 ganic matter, which must also be conceded as inol>ablo. 

 Under such conditions, it is reasonable to suppose that 

 bacteria, on being evolved as the primordial cells, may 



