70 Synopsis of the Bacteria and Yeast Fungi. 



b. Cells spiral, Spirobacterja. 



1. Spirals flexile ... ... ... ... Spirocheete 



2. Spirals rigid ... ... ... ... Spirillum 



The division into sections A and B is founded upon a 

 mistake, since some of the forms in the latter are now 

 known to occur in a zooglrea. The Vibrio here mentioned 

 is distinct from Ehrenberg's "Vibrio, and included only V. 

 Rugula and V. serpens. 



This classification Cohn revised in 1875 (see Quart. 

 Jour. Micr. Sci., 1876, pp. 259-278), adding the genera 

 Sarcina, Ascococcus, Leptothrix, Beggiatoa, Crenothrix, 

 Streptococcus, Myconostoc, Cladothrix, and Streptothrix, 

 and moreover placing these and the old genera in company 

 with the analogous genera of Algse in one series, as Schizo- 

 phytse. But these changes attracted but little notice except 

 among specialists, and the arrangement given above, with a 

 few additions, is that familiar to the majority of the students 

 of Bacteria. 



The growth of views inconsistent with this classification 

 will be seen by the following resumi of a few of the con- 

 trary opinions. The earlier observers, whose opinions were 

 based on insufficient grounds, may be disregarded. 



J. Lister {Quart. Jour. Micr. Set., 1873, pp. 380-408, 

 pi. 19-21) gave an account of several experiments with 

 Bacteria, in which great precaution was taken to ensure 

 accuracy, and in one case, of a Bacterium which appeared 

 spontaneously in milk, he observed coccus, bacterioid, 

 bacillar, and leptothrix forms, and recognised their genetic 

 connection. 



Ray Lankester's investigation of Bacterium rubescens 

 (1873) has been already noticed. Few even of succeeding 

 writers have gone further in uniting different and apparently 

 distinct forms. See also his further observations in the 

 same journal (1876, pp. 278-283), and infra, p. 85. 



