100 



THE CYTOLOGY 



LIFE-HISTORY OF BACTERIA 



the bacillus was not clearly observed by some of the cytologists who used 

 bacteria of this type as material for the study of sporulation, and they accordingly 

 described the nuclear fusion, which precedes the formation of the spore, as 



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15 



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Fig. 41 



MATURATION OF THE SPORE 



A. Rough bacillus. The nuclear material from the four cells fuses sexually to form a 

 rod-like nucleus. This redivides into four units, of which three are eliminated and one 

 incorporated in the spore. The reduction process. 



B. Smooth bacillus. Two instead of four nuclear units take part, both within the same 

 cell. These fuse and then separate ; one is eliminated. 



an autogamous process. As it entails the fusion of nuclear material from more 

 than one cell, however, it may reasonably be considered to be sexual. In the 

 case of sporing baciUi of smooth morphology, which are unicellular but 

 possess two nuclear units in each cell, the fusion between these two units 

 can only be regarded as autogamous, unless it can conclusively be proved, as 



Fig. 42 



THE MATURATION OF THE SPORE 



(1) Clostridium welchii, vegetative cells, acid-Giemsa < 2800. 



(2) CI. welchii, nuclear fusion, acid-Giemsa x 3500. 



(3) CI. welchii, fusion cells, acid-Giemsa X 3500. 



(4) CI. welchii, maturing sporangia, acid-Giemsa x 1875. 



