456 



Annals New York Academy of Sciences 



Beyond this fact, a comparison over such long periods of tune gives the 

 following results: (1) The paleozoic strains of the Bacillus circulans have quite 

 a lot more biochemical characteristics than those described in the preceding 70 





^ 



Figure 1 (Top). Bacterium in the center of a thin section of a thickness of 15 ^u, enlarge- 

 ment 3600:1. 



Figure 2 (Bottom). Bacillus circulans from the Zechstein salt, enlargement 950:1. 



years. (2) It seems that the long, latent life of about 180 million years has 

 brought about no loss of characteristics for the Paleozoic species. (3) A loss of 

 characteristics was proved, however, for the Recent representatives of Bacillus 

 circulans, which have gone through a vast number of cell divisions. (4) Al- 

 though the differences in biochemical behavior are very distinct, there is an 



