I 



CAL 

 QAKOetH 



FURTHER STUDIES ON THE GROWTH CYCLE OF 



AZOTOBACTER 1 



DAN H. JONES 



Ontario Agricultural College, Guelph, Canada 



Received for publication February 6, 1920 



At the 1912-1913 meetings of the Society of American Bac- 

 teriologists the writer read a paper entitled "A Morphological 

 and Cultural Study of Some Azotobacter," using a series of lan- 

 tern slides of photomicrographs for illustration. The paper was 

 subsequently published in the Centralblatt fur Bakteriologie, 

 1913, and in the "Transactions of the Royal Society of Canada" 

 of the same year. 



Among the observations made in this paper was one regarding 

 the formation in azotobacter cells of two types of granules, one 

 type being stainable, and the other non-stainable, with various 

 bacterial stains. The type that was stainable appeared to 

 represent reproductive bodies or gonidia which on disintegration 

 of the mother cell were liberated, after which they grew into 

 normal azotobacter cells and reproduced by fission for a time 

 until later the cells became granular and again disintegrated with 

 the liberation of reproductive granules. The formation of these 

 reproductive granules with their liberation, on the disintegration 

 of the mother cell, appeared to the writer to constitute a 

 new type of multiplication for azotobacter distinct from the 

 usual method of fission characteristic of bacteria in general. 

 As no reference to such a method of multiplication could be 

 found in the literature, the observations were repeated a con- 

 siderable number of times to verify the above conclusions. 



In the Centralblatt for 1914 the writer published another 

 short article entitled "Further Studies with Some Azotobacter." 



1 Presented before the Society of American Bacteriologists, December 29, 1919. 



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THE JOURNAL OP BACTERIOLOGY, VOL. V, NO. 4 



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