GENERAL SYSTEMATIC BACTERIOLOGY 23 



Cohn's Classification of the Schizophyta (1875) 



a. Cells free or united into slimy families by an intercellular substance. 



Tribe I. Gloeogenae 

 b. Cells free or in twos or fours. 



c. Cells spherical Chroococcus Naeg. 



cc. Cells cylindrical Synechococcus Naeg. 



bb. Cells in resting stage united into amorphous slimy families. 

 0. Cell membranes continuous with intercellular substance, 

 d. Cells without phycochrome, very small. 



e. Cells spherical Micrococcus Hall, emended 



ee. Cells cylindrical Bacterium Duj. 



dd. Cells with phycochrome, larger. 



e. Cells spherical Aphanocapsa Naeg. 



ee. Cells cylindrical Aphanothece Naeg. 



cc. Intercellular substance formed of layers of cell membranes. 



d. Cells spherical Gloeocapsa Kg. Naeg. 



dd. Cells cylindrical Gloeothece Naeg. 



bbb. Cells united into definite slimy families. 



c. Cell families of a flat single layer of cells. 



d. Cells in fours in one plane. . . .Merismopedia Meyen. 

 dd. Cells irregularly grouped on surface of sphere, 

 e. Cells spherical, families broken into nets. 



Clathrocystis Henfr. 



ee. Cells cylindric Coelosphaerium Naeg. 



cc. Cell families, many layered, united into spherical cell bodies, 

 d. Number of cells definite. 



e. Cells spherical, in tetrads, colorless. 



Sarcina Goods 

 ee. Cells cylindric, not regularly arranged, with phyco- 

 chrome Gomphosphaeria Kg. 



dd. Number of cells indefinite, very large. 

 e. Cells colorless, very small. 



Ascococcus Billr. emended 

 ee. Cells with phycochrome, larger. 



Polycystis Kg. 

 Coccochloris Spr. 

 Polycoccus Kg. 



aa. Cells united into filaments Tribe II. Nematogenae Rab. 



b. Cell filaments always unbranched. 



c. Filaments free or felted together. 



d. Filaments cylindric, colorless, indefinitely jointed, 

 e. Filaments very slender, short. 



Bacillus Cohn 

 ee. Filaments very slender, long. 



Leptothrix Kg. em. /*f\VvVC>^/ 

 eee. Filaments thicker, long . .i?eogia<oo Trev. /v/^-^rkiT .■'^v 



