C. F. ROBINOW 



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50* 60' 



Fig, 3. The chromatin of germinating B. cereiis spores hxed ^vith os- 

 mium, hydrolysed with N HCl (60°, 8-10 minutes) and stained with SO2- 

 azure A. Magnification as indicated. 



The different species now presented are considered as varieties of B. 

 cereus. The varieties, sotto, thuringiensis and alesti, are strains in which 

 each sporulating cell produces a crystal as well as a spore (Hannay, 1953; 

 Hannay and Fitz-James, 1955), which crystals are toxic to insect larvae 

 (Angus, 1954; Toumanoff et al, 1955). 



