218 



INFECTIVE DISEASES. 



Involution forms are freely developed 

 cultures made in unsuitable media. The 





\ 





0' 



7*/o 



V 



<l,r' 



in old cultures, and in 

 bacilli possess numerous 

 flagella, and theii' 

 power of movement at 

 once distinguishes them 

 fi'om anthrax bacilli. 

 They can be cultivated 

 in the ordinary media 

 in the absence of oxy- 

 gen, but more readily 

 ■with the addition of 

 grape-sugar or glyce- 

 rine. E-adiating fila- 

 ments grow out from 

 the more or less spher- 

 ical colonies directlv 



i"iG. 101. B.iciLLi OF Quarter-evil x 1000. From 

 an agar culture (Frankel and Peeiffek). 



liquefaction commences. In the depth of 

 nutrient gelatine the growth occurs in two 

 or three days at 20° to 25° 0. towards the 

 lower part of the track of the inoculating 

 needle. The gelatine slowly liquefies, and 

 there is considerable formation of gas with 

 the development of a peculiar odour. Spore- 

 foivmation occurs freely in cultures, but not 

 in the blood of infected animals until after 

 death. 



Guinea-pigs inoculated with a pure- 

 culture, or with spore-bearing threads, die 

 in twenty-four to thirty-six hours. An em- 

 physematous infiltration with sanguineous 

 serum is produced at the seat of inoculation, 

 and the surrovmding muscles are of a dark 

 colour. The internal organs are more or less 

 congested. The bacilli are found in the 

 local exudation and in the surrounding 

 tissue, and some hours after death in 



Fig. 102. Pure-Cui.tuhe op 

 Bacilli of Quaeter-evil 

 IN Grape-sugar Gela- 

 tine (Frankel and 

 Pfeiffek). 



