74 Synopsis of the Bacteria and Yeast Fungi. 



in its Leptothrix form, after reaching a certain length, 

 shows a slow oscillating movement. At the ends of the 

 threads Micrococci arise, which unite in a zoogloea and 

 also grow into rods ; pieces of the end of the Beggiatoa 

 grow crooked, fall off, and form Spirillum-like fragments, 

 which swim about by means of flagella. 



Again, Beggiatoa rcseo-persicina, Zopf {Cohnia roseo-per- 

 sicina, Winter), also forms Micrococci ; these cocci are of 

 two sizes, which grow genetically one from the other. From 

 the cocci grow threads of very varied lengths. Similar 

 results obtain in Crenothrix. 



These three genera, Cladothrix, Beggiatoa, and Creno- 

 thrix, with Leptothrix, form the highest developments of the 

 Schizomycetes ; in them a distinction can be made out 

 between base and apex. The mode of vegetative multipli- 

 cation in this class of Fungi is always by bipartition (from 

 which circumstance, indeed, the name is derived) ; this 

 bipartition usually takes place in one direction, but occa- 

 sionally in two or even three. The cells are always enclosed 

 in a cell-wall ; this wall is usually composed of cellulose, 

 but in a certain group, viz. the putrefactive Bacteria, it 

 consists of a substance not much different from the cell- 

 contents, to which the name of mycoprotein has been given. 

 This shows a deviation from the vegetable cell in the 

 direction of the animal cell, and accounts for the discre- 

 pancies between earlier observers, some of whom, e.g. Dr. 

 Letzerich, always succeeded in obtaining the ordinary 

 cellulose reaction (a blue coloration with iodine and sul- 

 phuric acid), while others always failed. All the genera, 

 except the filiform ones, may be provided with flagella. The 

 reproduction by spores has been observed, not only in 

 Bacillus, but also in other forms, e.g. by Van Tieghem in 

 Leuconostoc, Spirillum, Spirochaeta, and Bacterium. There 



