xvii.] SEPTIC AND PATHOGENIC ORGANISMS. 209 



organisms are : (A) the common bacillus of hay infusion 

 is said by Buchner to be capable of transformation into 

 bacillus anthracis ; (B) a bacillus subtilis, present in the air, 

 which, although quite harmless in itself, assumes distinct 

 pathogenic properties when growing in an infusion of the 

 seeds of Abrus precatorius, becoming hereby endowed with 

 the power of causing severe ophthalmia (Sattler) ; (C) a 

 common mould, aspergillus, which harmless in itself, when 

 grown on neutral and alkaline material at about body- 

 temperature (38 C.) assumes, according to Grawitz, very 

 poisonous properties, producing in rabbits inoculated with it 

 death, with metastasis of aspergillus and its spores in the 

 various internal organs. 



There are in the literature of micro-organisms other cases 

 mentioned, in which such a transformation has been supposed, 

 but without any experimental proof, and we need not there- 

 fore trouble ourselves more about them. 



Let us now review seriatim the above three cases : 



(A) Dr. Hans Buchner in a paper, which for many reasons 

 may be considered an important one, " Ueber d. experim. 

 Erzeugung des Milzbrandcontagiums, &c.," published in the 

 Sitzungsberichte d. math, physik. Classe d. k. Bair. Akademie d. 

 Wiss. 1880, Heft iii. p. 369, states that he succeeded in 

 transforming the common bacillus of hay infusion, the hay 

 bacillus, into the bacillus anthracis. 



The hay bacillus and the bacillus anthracis rank together 

 morphologically under that form which Cohn has named 

 bacillus subtilis. 



The two are, however, not quite identical in morphological 

 respects. The hay bacillus is a minute rod or cylindrical- 

 shaped bacillus, which by elongation and division produces 

 chains and further threads just like the bacillus anthracis, but 

 in the latter (i.e. bacillus anthracis) the bacilli and their 



p 



