72 CLASSIFICATION OF TIIK BACTERIA 



brought to light, they then asserted pleomorphism to be peculiar to the non- 

 pathogenic bacteria. Even this restricted assumption has, however, given \\ay, 



undoubted pleomorphism was proved in 1882 by ARCHANGELSKI (I.) and 

 ROLOFF (I.) for Jidcil/ns Hii'lirari*. and by Fried lander for Pneumobacillus ( 33) ; 

 in 1883 by TH. KIILKHS (I.) for the H'tmcliliraml Imcilltis (of symptomatic 

 :in(lii-:ix) ; in 1889 by E. MET8CHNIKOF1 ( I I .) for his newly discovered pathogenic 

 Sj.'ii-ol.nr'tlln- '!//(<>!' Daphnia ni.-igna); and in 1892 by F. FISCHEL (I.) 



for Bacilli'* tuberculosis. It may be remarked en passant that Metschnikoll' 

 prefaced the report of his discoveries with a short review (well worthy of perusal) 

 of the development of the pleomorphism theory. 



At the end of the "seventies" (John had established beyond doubt the ability 

 of certain fission fungi to produce endospores, and thereby obtained reliable 



FIG. 31. Bacterium Zopfii, Kurth. 

 Gradual changes in the same thread ohserved under the microscope. 



A, thread without apparent articulation ; B, breaking up into rods which finally form 

 cocci In C ; a-e are corresponding- cells. (Aft<-r Kurth.) M:ii;ii. 740. 



means of differentiation. Very soon after, De Bary showed that several of 

 the species which do not form endospores protect themselves from injurious 

 influences in another way, viz., by the formation of arthrospores. Hence a 

 classification was devised in 1883 by VAN TIEOHEM (II.), which was further 

 developed by DE BARY (I.) and HUEPPE (II.), in 1886, and in which two main 



ips were recognised, viz., the endospore- and arthrospore forming bacteria. 

 The second group also comprises all the species in which the formation of repro- 

 ductive cells has not yet been observed. Fuller details of this system can be 

 seen in Hueppe's treatise, but the system need not be further developed here, as 

 it has not yet been generally accepted in scientific circles. 



fuller information Hoarding Van Tieghem's system, as well as for parti- 

 culars relative to the systems proposed by P. Miquel and by Woodhead in 1891, 

 which maybe properly design a tod as "diagnostic tables," reference may be made 

 to \V.\ lib's (III.) readily accessible and comprehensive treatise. The new system 

 published by \V. .M H;ILA (1 I.) in 1X1,0 may also be simply referred to. 



In this connection there remains only one remark to be made, and this 

 concerns the term Bacillus. This word lias been hitherto employed by us to 

 designate only a well-defined form phase of cell, vi/.., the cylindrical bacterial cell, 

 the length of which is at least double the breadth. Hueppe's system, however, 

 applies the generic name /)'r/r/////.v only t<> s.i< b rod- M have been proved capable 



