LIFE-CYCLES IN BACTERIA 127 



and the occasional swelling of the bacterial filaments which accompanied 

 their presence, to be evidence of a parasitic or symbiotic condition between 

 the L-organism, as it was termed, and the bacterium. Diencs (1939 ct sc(].), upon 

 the other hand, believed the L-organism to be a gonidial stage in the life-cycle 

 of the bacterium. He claimed that the minute colonies were liberated from 

 the swellings upon the bacterial threads, and that the tiny, component 

 organisms grew up into Str. nuniilifonnis. Klicncberger stated that the 

 L-organism could be subcultured upon artificial medium for several years, 

 without reverting to a bacterial condition. 



Dienes also claimed that the swollen cells, which hberated the L-gonidia, 

 were the result of sexual fusions between filaments, and that similar swellings 

 occurred at the point of contact of Proteus swarms (Chapter VI). Similar 

 swollen filaments have been observed to occur in a variety of bacterial genera, 

 and L-organisms have been found in cultures of Neisseria {^ofiorrlioeae and 

 Fusijormis iiecrophorus. 



Studies with the electron microscope support the life-cycle hypothesis, 

 and there is little doubt that the L-organisms are in fact a gonidial stage in 

 the life-cycle of these bacteria. Klieneberger has herself adopted this view 

 in a recent paper (1949), and claims that the reproductive bodies arise from 

 a sexual process. 



The main difference between this phenomenon and gonidial reproduction 

 in many other bacterial groups (Section F, above) is the apparent capacity 

 of the L-stage to reproduce itself for many generations without returning to 

 the bacterial condition. 



Fig. 55 



THE L-STAGE IN THE BACTERIAL LIFE-CYCLE 



(I), (2) Colonies of the L-form of Fusiformis necrophorusx 200. This gonidial stage 

 reproduces for some time without reverting to the bacterial form. 



(3) A colony of the L-form, fixed and stained, in sifux 2000. 



(4) Fusiformis necrophorus, the bacterial form, showing reproductive swellings. Giemsa 

 )k 3500. 



