IN SUSCEPTIBLE ANIMALS. 



43 1 



cubating oven a rather thin, transparent, grayish-white or yellowish, 

 waxy layer is developed in the course of a few days. According to 

 Bunzl-Federn, the bacillus of fowl cholera and that 

 of rabbit septicaemia grow upon potato, while the 

 bacillus of Wildseuche, Schweineseuche, and Biif- 

 felseuche do not. According to 

 Caneva, none of the bacilli of this 

 group grow upon potato. The 

 same author states that the growth 

 in milk is scanty and does not 

 produce coagulation, while Bunzl- 

 Federn finds that the bacillus of 

 fowl cholera and of rabbit septi- 

 caemia produce coagulation and 

 the others do not. These differ- 

 ences are not, however, consid- 

 ered by the author last named as 

 sufficient to establish the specific 

 difference of the bacilli from these 

 diff erent sources. He looks upon 

 them rather as varieties of the 

 same species. Bunzl-Federn has 

 also ascertained that when cul- 

 tivated in a peptone solution all 

 of the bacilli of this group, with 

 the exception of that obtained 

 from the so-called Buffelseuche, 

 give the reaction for phenol and 

 for indol the bacillus of Buffel- 

 seuche gives the indol reaction only. Development in bouillon is rapid 

 and causes a uniform turbidity of the fluid. Cultures of this bacillus 

 may retain their vitality for three months or 

 more when kept in a moist condition ; but 

 the bacillus usually fails to grow after having 

 been kept for a few days in a desiccated con- 

 dition ; according to Hueppe, it may resist 

 desiccation for fourteen days. The thermal 

 death-point, as determined by Salmon for 

 the bacillus of fowl cholera, is 56 C. , the time 

 of exposure being ten minutes (55 C. with 

 fifteen minutes' exposure Baumgarten). It 

 is not readily destroyed by putrefaction (Kitt). 

 A solution of mercuric chloride of 1 :5,000 

 destroys it in one minute, and a three-per-cent solution of carbolic 



PIG. 130. Bacillus 

 septicaemias haemor- 

 rhagicae; stick culture 

 in nutrient gelatin, 

 end of four days at 16- 

 18 C. (Baumgarten ) 



Fia. 131. Bacillus 

 of Schweineseuche ; 

 old stick culture 

 in nutrient gela- 

 tin. (Schutz.) 



FIG. 132. Bacillus of swine 

 plague; colonies on gelatin 

 plate, end of seven days. 

 X 00. (Smith.) 



