2o6 BOTAXICAL GAZETTE [skptkmbek 



Discussion 



The results of this study on the morphology of the organisms- 

 of nitrosofermentation, active in the North American soils, are 

 not easily reconciled with the results obtained 28 years ago by 

 Jordan and Richards. The discrepancy between the results is 

 undoubtedly to be ascribed to two reasons: (i) incomplete de- 

 scription of the organisms isolated from sewage in Massachusetts, 

 and (2) the probable presence in those cultures of organisms 

 capable of transforming nitrites to nitrates. The possibility of 

 a mixed culture was admitted by Jordan and Richards on the 

 basis of the absence of nitrite formation during nitrification. 



The resemblance of the megalococcus isolated by Winogradsky 

 from the South American soils to the megalococcus for the North 

 American soils is quite striking. Excepting the slight difference 

 in size existing between the two forms, all other characters are 

 common to both. The variation in the life cycle of the two organ- 

 isms is probably only apparent, since the true cocci, which have 

 been named j3 by the author, might have escaped Winogr.a.dsky's 

 attention. It is to be regretted that the Russian investigator 

 was not able to study the nitroso-organisms from the New World 

 as thoroughly as he did those from the Old World, and that he was 

 obliged to publish only an abridged description of the former 

 types. In the present work an attempt was made at the comple- 

 tion of his work, and results have been reached which corroborate 

 the postulations to be made from his findings, in such a way filling 

 a gap in our knowledge of the distribution of the nitrite-forming 

 organisms. That the organism isolated in Wooster can be classed 

 as a species of the genus NUrosococciis seems to be justified bs' 

 these findings. The comparative study of the species of the genus 

 NUrosococciis will have to be deferred to a time when a careful 

 study will be possible of the organisms of nitrosofermentation in 

 South America and Australia. 



LITER.\TURE CITED 



1. Beijerixck, M. W., Kulturversuche mit Amoben auf festen substrate. 

 Centr. Bakt. I. 19:257-267. i8g6. 



2. BoNAZZi, A., On nitrification. II. Intensive nitrite formation in solution. 

 Jour. Bacteriology 4:43-60. iqiQ- 



