152 MICRO-ORGANISMS AND DISEASE. [JHAP 



and others on the bacillus anthracis ; Arloing, Thomas, and 

 Cornevin on the bacillus of symptomatic charbon ; of Koch 

 on the bacillus of tuberculosis ; of Israel on actinomyces, 

 and many others ; and particularly would I refer to the many 

 valuable suggestions and considerations expressed by v. Nageli 

 in these respects in his book, Die niederen Pilze, Miinchen, 

 1877 and 1882. 



While from these observations it would appear that both 

 septic and pathogenic micro-organisms are capable of suffering 

 some modifications in their morphological and physiological 

 behaviour, it is nevertheless still an open question whether an 

 organism which under ordinary conditions is only associated 

 with putrefactive changes in dead organic material, and which 

 cannot under these ordinary conditions grow and multiply 

 within the living body, can, under certain extraordinary cir- 

 cumstances, become endowed with the power of growing and 

 multiplying within the body of a living animal, creating 

 there a pathological condition, inducing there an infectious 

 disease. 



Three distinct septic micro-organisms have, after n amerous 

 experiments and careful observations, been mentioned, as being 

 capable when growing under certain extraordinary conditions of 

 assuming pathogenic properties. These three 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-tempera- 

 ture (38 C.) assumes, according to Grawitz, very poisonous 

 properties, producing in rabbits inoculated with it "death, with 

 metastatis 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 therefore 

 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, pliysik. classe d. Jc. Bair. Akademie d. 

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



