ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 237 



in tlie form of one or more symptomatic tumours at points remote from 

 the place of inoculation ; witli a very strong dose a tumour imme- 

 diately appears at this point, the general condition of the patient 

 becomes rapidly serious, and if life lasts sufficiently long, one or more 

 tumom's may arise in different parts of the muscles. (4) The results 

 of the intravenous process of injection similarly differ with the amount 

 of virus employed. With a minute quantity general disturbances are 

 produced, which disappear in two or three days, leaving the subject 

 proof against the effects of further inoculation ; this is caused by 

 an abortion of the anthrax. With a considerable dose, symptomatic 

 anthrax is fully developed, and tumours appear, invariably causing 

 death. 



These different modes in which the poison may be seen to act are 

 thus explained. In the case in which intravenous injection is not fatal 

 the bacterium probably multiplies in the blood, but is prevented by 

 the endothelium of the vessels from entering the connective tissue. 

 The serious consequences which always follow introduction of the 

 poison into the latter tissue — extending to the production of a local 

 tumour, even after a preventive inoculation by inti-a venous injection — 

 show this to be really the point at which the virus attacks the system. 

 When tumours follow intravenous injection, the bacterium must have 

 passed in some way into the connective tissue, whether by rupture of 

 other coats or otherwise. The abortive result of inoculation by way 

 of the respiratory system, as well as by way of the veins, is due to the 

 same cause, viz. the penetration into the blood of the bacterium 

 through the lining-epithelium and its development in this harmless 

 position. 



A short account of some public experiments performed by the 

 same three investigators at Lyons is given by Bouley.* The first 

 series were intended to show immunity against symptomatic anthrax 

 produced by previous intravenous inoculations at different periods. 

 Thus a ram inoculated in the thigh with 5 cc. of the virus died in two 

 days, but a calf, vaccinated fourteen months previously by intravenous 

 injection, showed not the smallest sign of evil effects after injection of 

 1 mm. in the same manner as in the former case ; the same immunity 

 was exhibited by another calf inoculated with 5 mm. eleven months 

 after vaccination ; so also with a calf sixteen days old whose mother 

 had been inoculated twenty-seven days after the commencement of 

 gestation (six months before the birth of the calf). An ewe, vaccinated 

 fifteen days previously by injection into the trachea, behaved similarly 

 on injection of 5 mm. into the thigh. A second series of experiments 

 showed the refractory behaviour of certain animals towards the disease ; 

 thus subcutaneous and intramuscular injections produced no effects 

 on a pig, a white rat, a dog, and a rabbit, but the same operation 

 performed at the same time killed a six months' calf. 



The method of vaccination here adopted differs from that employed 

 by Pasteur against the other form of anthrax (bacteridian anthrax) in 

 not employing a mitigated form of the virus, but introducing the virus 

 in its natural condition into surroundings (i.e. the blood-vessels) not so 



* Comptes Kendus, xcii. (1881) pp. 1383-7. 



