228 MICRO-ORGANISMS AND DISEASE. [CHAP. 



general mycosis, and this power they possess ab initio ; other 

 kinds of aspergillus do not possess this character and cannot 

 acquire it under any conditions. 



Thus also this third case of a transformation of a common 

 into a specific organism due to altered conditions of growth 

 falls to the ground. 



It might be now asked, how about those cases in which by 

 injection of very small quantities of putrid organic substances, 

 pyaemia or septicaemia has been produced in rodents ? Take 

 the case of Davaine's septicaemia in rabbits. This disease 

 has been produced in rabbits by Davaine, Coze and Feltz, 

 and by many other observers, by injecting into the subcu- 

 taneous tissue of healthy rabbits small quantities of putrid 

 ox's blood. The rabbits die in the course of a day or two, 

 and their blood is found teeming with minute organisms, 

 which prove to be bacterium termo ; every drop of this blood 

 possesses infective properties ; when inoculated into a rabbit 

 it produces septicaemia with precisely the same appearances 

 as before. Pasteur and Koch have succeeded in producing 

 septicaemia in mice and rabbits, and especially in guinea-pigs, 

 by inoculating them subcutaneously with garden earth or with 

 putrid fluid. This is Pasteur's septicaemia, or Koch's malig- 

 nant oedema ; it is characterised by oedema at the seat of 

 inoculation, and spreading hence in the subcutaneous tissue 

 of the surrounding parts. The animals die generally in 

 twenty-four to seventy-two hours. 



Koch has produced by injection of small quantities of 

 putrid fluids into the subcutaneous tissue of mice a peculiar 

 septicaemia ; the animals sometimes die in forty to sixty hours, 

 and the white corpuscles of the blood are found crowded 

 with exceedingly minute bacilli. Koch succeeded also in 

 producing a pyaemia in rabbits by injection of putrid fluids, 

 and this pyaemia is characterised by zoogloea of minute 



