214 MICRO-ORGANISMS AND DISEASE. [CHAP. 



ture of 35 to 37 C., gradually loses its pathogenic properties. 

 Of this assertion I have said already a great deal in my 

 Report for 1881 1882, and I mention it here merely in 

 connexion with Buchner's other assertions. I have shown, 

 that even assuming that Buchner has had in all his cultures 

 the true bacillus anthracis, but for which there is no definite 

 proof, as Koch has so ably pointed out in his critical review 

 of Buchner's work ( Mittheilungen aus dem k. Gesundhdtsamte, 

 Berlin, 1881, End. I.), Buchner having tested his cultures 

 on white mice only, has fallen into a serious error, for, as I 

 have shown (Reports for 1881 1882), a culture of bacillus 

 anthracis may have become quite harmless to white mice, but 

 be still very virulent to other animals. In fact, therefore, 

 Buchner's result does not require for its achievement more 

 than one culture, provided this has been kept for several days 

 or weeks without spore-formation, as was the case in 

 Buchner's experiments. 



As regards Buchner's statement that by successive cul- 

 tivation of bacillus anthracis at 35 to 37 C., this assumes 

 the morphological and physiological characters of hay bacillus, 

 I agree with Koch in regarding this as a complete error. If 

 the cultures are quite safe from contamination nothing of 

 the sort ever happens. I have now for several years carried 

 on such cultures, and have not seen anything of the sort. 

 It is of course clear that if by any accidental contamination, 

 say at the time of inoculating a fresh tube, a motile septic 

 non-pathogenic bacillus, with which, or with the spores of 

 which, the air sometimes abounds, is introduced, every new 

 culture established from this one will abound in this bacillus 

 and as it grows quicker and more easily than the 

 bacillus anthracis, the next cultivations become barren of 

 all the bacillus anthracis, and only the non-pathogenic motile 

 bacillus will be found present. This criticism has been 



