18 THE FUNGI WHICH CAUSE PLANT DISEASE 



will also of course receive many additions of forms not as yet 

 known. 



No system of classification can yet be said to have general 

 acceptance and all classifications now in vogue will undoubtedly 

 undergo minor changes and perhaps changes in fundamental 

 conception. 



The system of Migula" meets probably with most favor. 

 With the omission of genera of little import pathologically, and 

 with the introduction of the order Myxobacteriales, it is as follows: 



SCmZOMYCETES (p. 3) 



Fission plants, without phycochrome, dividing in one, two or 

 three directions of space. Reproduction by vegetative multiplica- 

 tion. Resting stages, endospores, exist in many species. Motility 

 by means of fiagella in many genera. 



Key to Okders, Families, and Genera of Schizomycetes 



Cells without sulphur or bacterio-purpu- 



rein Order I. Eubacteriales. 



Cells ia free condition gobular; in di- 

 vision somewhat elliptical I. Coccaceae, p. 21. 



Nonfiagellate 

 Division in only one direction, 



cells single, in pairs, or chains 1. Streptococcus. 

 Division in two directions; cells 



may remain in plates 2. Micrococcus, p. 21. 



Division in three directions cells 

 may remain in bale-like 



packets 3. Sarcina. 



Flagellate 



Division in two directions 4. Planococcus. 



Division in three directions. . 5. Planosaicina. 

 Cells long or short, cylindrical, 

 straight, division in one direc- 

 tion II. Bacteriacese, p. 21. 



Nonfiagellate 6. Bacterium, p. 21. 



Flagellate 



Fiagella diffuse 7. Bacillus, p. 37. 



Fiagella polar 8. Pseudomonas, p. 22. 



