THE HISTORY OF BACTERIOLOGY. 63 



particular species. (5) The long non-wavy vibrios (vibrio, 

 bacillus, &c.), are related to the more delicate beggiatoa 

 (oscillaria). (6) The shorter vibrios and spirilla, which 

 correspond in both form and motion to the oscillariae and 

 spirulinae, he was unable to localize in his system of classifi- 

 cation. 



In 1857 Naegeli collected all the forms then known, which 

 had certain characteristic physiological features in common, 

 into a group which he termed Schizomycetes or fission fungi, 

 a group which is now fully recognized by botanical mor- 

 phologists and physiologists. He included all those lower 

 forms of plant-life in which chlorophyll was absent, and 

 which contained carbon, oxygen, hydrogen, and nitrogen in 

 definite proportions, which elements they were not able to 

 assimilate and utilize in building up their own substance 

 from inorganic materials. They, like the other fungi and 

 animals, can utilize as food only such material as is presented 

 to them in the form of living or dead organic matter held 

 in solution, or combined with a considerable quantity of 

 water. The processes going on within their protoplasm are 

 so intimately connected with oxidization that they usually set 

 free no uncombined oxygen, and this characteristic feature 

 along with their want of chlorophyll colouring matter Naegeli 

 looked upon as the special feature by which they might be dis- 

 tinguished from ordinary fungi. Amongst his fission fungi 

 he placed the forms bacterium, vibrio, spirillum, sarcina, the 

 mother of vinegar, the yeast fungus, the organism associated 

 with the silkworm disease a small colourless oval organism, 

 somewhat resembling a yeast, which he named Nosema 

 bombycis most of which were characterized by the features 

 which are now recognized as belonging to the fission fungus 

 group. The relation of these to disease and fermentation 

 Naegeli declined to discuss. 



Although Leeuwenhoek had described certain micro- 

 organisms in the tartar of the teeth and in various secre- 

 tions and excretions so accurately and minutely, it was not 

 until 1837 that any definite attempt was made to associate 

 them with the products of a disease ; in that year, how- 

 ever, Donne described an Infusorian, which he likened 

 the vibrio lineola of Miiller, as occurring in pus in 

 syphilitic diseases. This he thought at first was simply 

 a vibrio associated with the putrefaction of the pus, 



