DE BARY AND HUEPPE'S CLASSIFICATION. 91 



the relationship of the Scliizomycetes to other organisms, but with 

 the separation of the former into genera, we must confine ourselves 

 to remarking that the new classification in the said treatise rested 

 too exclusively on morphological characters to be of practical value. 



69. De Bary and Hueppe's Classification. 



Gradually an accumulation of facts arose which afforded a basis 

 whereon a new system of grouping the fission fungi was attempted. 

 Differentiation based on cell form only was still considered justifi- 

 able up to 1878, but could no longer be maintained in the face of 

 incontrovertible observations made, in the course of the following 

 years, with absolutely pure cultures of various species of bacteria, 



and all leading 



to the same ^-"''f-w-.-*^^ 



conclusion, that ' 



ZdtfifaUon 'of 

 form, unques- 

 tionably does 

 occur in the 

 fission fungi. 

 This know- 

 ledge is the 

 result of vari- 



may be men- 

 tioned- in 1870 FIG. 30. -Bacterium merismopedioides. 

 that of F CH Found in the mud of the river Panke (Berlin). 



HANSEN (II ^ on J - A thread form breaking up into : 2. long rods ; 3. short rods ; 

 . ^ ' . 4. cocci; 5. a chain formed of rods of different lengths. 



Bacterium aceti (After Zopf.) Magn. 7 oo. 

 and B. Pasteur- 



ianum; in 1882 those of W. ZOPF (III.) on Bacterium merismo- 

 pedioides (Fig. 30), and by H. BUCHNER (VI.) on Bacillus subtilis ; in 

 1883 that of KURTH (I.) on Bacterium Zopfii (Fig. 31), afterwards 

 also examined by H. SCHEDTLER (I.) ; in 1885 that of G. HAUSER (I.) 

 on a few species of putrefactive bacteria of the genus Proteus ; 

 and others. The adherents of Koch at first unconditionally 

 opposed the theory of the pleomorphism of bacteria ; but, not 

 being able to sustain this view in the face of the facts brought 

 to light, they then asserted pleomorphism to be peculiar to the 

 non-pathogenic bacteria. Even this restricted assumption has, 

 however, given way since undoubted pleomorphism was proved 

 in 1882 by ARCHANGELSKI (I.) and ROLOFF (I.) for Bacillus 

 anthracis, and by Friedlander for Pneumobacillus ( 33); in 1883 

 by TH. EHLERS (I.) for the Rausclibrand bacillus (of symptomatic 

 anthrax); in 1889 by E. METSCHNIKOFF (II.) for his newly dis- 



