FIELD NATURALISTo' CLU3. 27 



CLUB PAPERS. 



THE SCHIZOMYCETES. 



By Beaven Rake, M.D. (Lond.) 



OUR knowledge of bacteria has advanced so rapidly during the 

 last twenty years, that there is a danger that in this as in all 

 good movements enthusiasts may claim too much, and that 

 over-zeal on the pai't of some may bring bacteriology into dis- 

 repute. I refer to a tendency which exists to immediately 

 discover a specific germ for every known disease. That this is 

 premature will appear in the course of this paper, but there is no 

 doubt that an intelligent study of bacteria is of the greatest 

 importance to the physician, the surgeon, the farmer, the manu- 

 facturer, and indeed to all who are concerned with the lives of 

 animals or vegetables. It therefore seemed that the subject was 

 not unsuitable for the consideration of the Field Naturalists' 

 Club. 



The discovery of micro-organisms is no new thing. In 1683 

 the Dutch observer Leeuwenhoeck described organisms in saliva 

 and putrid water, probably corresponding with what are now 

 recognized as vibrio and leptothrix. For the next two centuries 

 these organisms were the subject of much controversy. At one 

 time they were regarded as animals, at another time as vegetables, 

 while some observers doubted whether they were alive. 



In 1773 Muller suggested a classification and others followed 

 his example during the first half of this century. To Cohn, 

 however, belongs the credit of first satisfactorily classifying the 

 bacteria in 1872 and recognizing their position in the vegetable 

 kingdom. But the twenty years which have elapsed since Cchn's 

 researches have brought about a further change of opinion as to 

 the position and classification of bacteria. 



They are now regarded as belonging to the Schizomycetes or 

 fission-fungi which come under the achlorophyllous division of 

 the class protophyta of the group thallophytes. In other words 

 bacteria are minute cellular plants, which increase chiefly by 

 division and are without chlorophyll. 



Owing to this absence of chlorophyll bacteria are unable to 

 split up carbon dioxide into its elements, like the higher vegetable 

 cells, but on the other hand they differ from animal cells by being 

 able to obtain their nitrogen from ammonia compounds. Nencki 



