CLASSIFICATION AND DESCRIPTION OF SPECIES. 



479 



basis for classification into genera or species. The mode of repro- 

 duction is not sufficiently known to afford a better means for 

 distinction than the other morphological appearances taken alone ; 

 nor can we depend upon physiological action, which is held by 

 many to vary with the change of form, according to altered 

 surroundings. 



FIG. 196. 



CLADOTHRIX DICHOTOMA. A. Branched Schizomycete : (a) Vibrio-form ; (b) Spiril- 

 lum-form [slightly magnified]. B. Screw-form at the ends : (a) Spirillum- 

 form ; (6) Vibrio-form. C. Very long Spirochseta-form. D. Branch fragment, 

 at one end Spirillum-form, at the other Vibrio-form. E. Screw-form : 

 (a) Continuous ; (6) Composed of rods ; and (c) Cocci. F. Spirochseta-form : 

 (a) Continuous ; (6) Composed of long rods ; (c) Short rods ; and (d) Cocci 

 (Zopf). 



Zopf, who has warmly supported the pleomorphism of bacteria, 

 has suggested as a result of his investigations a division of the 

 Schizomycetes, Spaltpilze, or Fission -fungi, into the following four 

 groups : 



