July 3i, 1916 Life Cycles of the Bacteria 687 



as reproduced in figures 1 to 3 (PL A) and 8 (PI. B), show the same fact 

 much more clearly. In all these preparates many cells are in a conjunct 

 stage, which can not be explained by the assumption that this conjunction 1 

 is only accidental. Most of these illustrations have been made from con- 

 tact preparates taken directly from 4-day-old colonies. Smears made 

 in accordance with the "standard methods" probably would have 

 destroyed most of these connections. But also in this case it was still 

 more the effect of our theoretical blinders which prevented an earlier 

 seeing and understanding of this fact, which, like the budding of the 

 bacteria and the formation of the symplasm, has not only actually been 

 seen by many bacteriologists but also has been unknowingly reproduced 

 in several illustrations in our daily used textbooks. 



So far as we are aware, only one author has spoken of a similar observa- 

 tion. In 1892 Forster (6) found occasionally that Chromatium Okenii 

 sometimes entered into some "primitive copulation." Among the draw- 

 ings accompanying his paper, a sketch made from a photomicrograph 

 seems to us most trustworthy. Its conformity with our Azotobacter 

 illustrations is practically complete. Observations in the hanging-drop 

 clearly showed that there is some interference between the plasmatic sub- 

 stances in the conjunct cells or even some direct mixing of them. 



The determination of the actual physiological significance of this 

 conjunction must be left, of course, to a more thorough investigation. 

 At present we merely wish to add and to emphasize that this process is 

 by no means such an exception as might be deduced from Forster's 

 statements and from the silence observed in this direction in our text- 

 books. The conjunct stage seems to be of no less general importance 

 and occurrence in bacterial life than the formation of the symplasm 

 Not only normal cells and regenerative bodies but also exospores 

 have been frequently found in conjunction. And if we only succeed in 

 forgetting for a moment our most cherished theories and simply try to 

 look at the facts as they are, we find at once that the formation of the 

 symplasm and the conjunction of the cells are nothing else than two 

 modes of mixing plasmatic substances temporarily inclosed in separate 

 cells and that evidently the continuity and rejuvenescence of the living 

 matter in the bacteria is just as much dependent on this process as in 

 the case of all other organisms. 



A thorough study of the relations existing between the conjunct and 

 symplastic stage will be the first object of our further investigations in 

 this line. We hope that experiments with well-defined varieties and 

 species will soon furnish a correct insight. The ease with which the 

 ' ' flakes" of the symplasm can be isolated is, of course, very advantageous 

 for these, as well as for systematic, studies. 



1 We prefer the new term conjunction instead of " copulation " or " conjugation, " because frequently more 

 than two cells unite and no sexual differentiation so far has been observed. 



