juiy 3i, 1916 Life Cycles of the Bacteria 699 



That the discovery of the complete life cycles of the bacteria solves 

 also some problems in general biology has been indicated earlier in this 

 paper, when Fokker's theory (5) concerning the development of bacteria 

 from granules in milk or blood was discussed. It may be added that 

 also those much doubted and disputed strange observations of Bastian 

 (2, 3), so persistently and extensively defended by their discoverer, now 

 are coming under entirely new aspects. Readers interested in this ques- 

 tion should compare especially Plates IV and V of Bastian's "Nature and 

 Origin of Living Matter" (2) and those on Plates X and XI of his "Evo- 

 lution of Life" (3) with our illustrations of the different kinds of sym- 

 plasm and regenerative bodies. Figure 33 of the last-named plate (XI) 

 looks practically like a reproduction of our preparate shown in figure 14 

 (PI. C). Bastian was wrong, of course, when he considered those large 

 cells as being some torula form; but we know that De Negri (16) made 

 the same mistake recently, which indeed is quite excusable. That the 

 budding large cell in our figure 14 is really nothing else than a type of 

 growth of a spore-forming bacillus will probably even now be doubted 

 by one or the other bacteriologist. It is superfluous to point out that 

 we do not share Bastian's ideas concerning abiogenesis. Our standpoint 

 in this case is the same as in regard to Fokker's hypotheses. The weak 

 points in Bastian's experiments are sufficiently clear to every expert 

 reader of his books. This, however, should not lead to discarding indis- 

 criminately all his undoubtedly carefully made microscopical observa- 

 tions. 



It goes without saying that we will readily furnish subcultures of the 

 strains used in our studies to everyone who asks for them. But it proba- 

 bly would be still more interesting and surprising to our fellow bacteri- 

 ologists if they would make some investigations with their own well- 

 known stock cultures along the lines discussed in the foregoing pages. 

 Even a renewed microscopical study of old stained preparates may be- 

 come very instructive. For example, the senior author also did not know 

 that for more than 11 years he had in his collection, patiently waiting 

 to be photographed, that fine preparate now shown in figure 6 (Pi. A) 

 until, as stated before, he decided to take down his " theoretical blinders." 

 We have already mentioned that a careful study of the illustrations 

 contained in our daily used textbooks will now reveal several things 

 which we were so very well trained not to see. Certainly the German 

 philosopher Lichtenberg made a very wise remark when he said: 



Was jederman fur ausgemacht halt, verdient am meisten untersucht zu werden. 



SUMMARY 



A comparative study of 42 strains of bacteria has shown that the life 

 cycles of these organisms are not less complicated that those of other 

 micro-organisms. As representatives of practically all groups of bacteria 

 have been tested and all, without exception, behaved essentially in the 



