8o 



THE CYTOLOGY AND LIFE-HISTORY OF BACTERIA 



form of an, apparently, disorganised mass oi granular material from which 

 the rod-like nucleus is reformed. These granules may be identical with those 

 which, in some cases, can be discerned in the completed rod. 



(Reproduced from the Journal of Ihi^uiu- and Journal of Gciural Microbiology.) 



Fig. 37 



TYPES OF ROD-LIKE NUCLEUS 



Top Left — Early stages in the maturation of the resting nucleus in Bact. coli. 



Bottom Left — Similar stages in Bact. cerogenes (the dark surface material is capsular) 



Right — Rod-forms enclosed in the developing spore of CI. tetani. 



Acid-Giemsa x 3000. 



The rod-like nucleus in streptomyccs and spore-bearing bacilli is apparently 

 a fusion nucleus and can result from a process o'i sexual conjugation 

 (Chapter VI). 



In non-sporing genera, while the nucleus is in this condition, the length 

 of the individual bacteria is often very variable, and they range from short, 

 almost coccal cells, to filaments of considerable length. Cell-division appears 

 to lack the regularity of other nuclear phases. 



