ZOOLOGY A.ND BOTANY, MICROSCOPY, ETC, 93 



vessels. In the case of five of them the inoculations were made some 

 weeks or months beforehand ; the remaining were inoculated only a 

 few days before the final experiment. 



The whole eight were then injected with from 15 to 70 c.c. of blood 

 taken from an infected sheep either before or just after death (this 

 amount is said to represent from 12,000 to 200,000 millions of bacilli). 



The respiration immediately became very painful, the head was 

 extended, the mouth was opened and foamed, its mucous membrane be- 

 came cyanosed ; a moaning expiration was kept up ; sudden panting 

 movements of the sides were accompanied by a very rapid pulse and 

 stupor ; defecation was repeated several times, becoming diarrhceal. 



On examining the blood of a vessel of the ear for the bacteria 

 fifteen minutes after the transfusion, they are found, but few in 

 number, and fewer than would be the case if the amount introduced 

 were regularly spread throughout the mass of the blood. After from 

 two to six hours they cannot be found at all. 



Of the sheep thus treated one developed true splenic fever, and 

 died after the unusually short period of about sixteen hours. It was 

 one of those which had been vaccinated but shortly before the experi- 

 ment, and had received the maximum quantity of infected blood, viz. 

 70 c.c. Another, which had been inoculated five times previously, 

 and received 65 c.c. of infected blood, also died in twelve hours, but 

 not of true splenic fever, for the bacteria did not grow, and two hours 

 after death scarcely any trace of them was to be found. Four of the 

 other sheep also died in from forty-six to 100 hours, not of the 

 splenic disease, but from a purely local proliferation of the bacteria, 

 viz. in the pia mater, which gave rise to meningitis. The bacteria were 

 scarcely to be found in any of the parenchymatous organs (lungs, 

 spleen, &c.) after death, but they occurred in great abundance in the 

 vessels of the pia mater and their sheaths, showing the peculiar charac- 

 ters of being long, bent, or twisted, and sometimes containing spores. 

 They produced an inflammation which sometimes extended over the 

 brain, and even into the ventricles. No pus was formed. The bacteria 

 found here were strongly infectious, rapidly killing subjects inoculated 

 with them, while blood from other parts of the body failed entirely to 

 produce that effect. The two remaining sheep recovered entirely, 

 and furnished good meat, which was eaten. 



The chief conclusions which are deduced from these experiments, 

 with regard to the action of bacteria in such cases, are : — (1) The 

 bacilli introduced into the circulation rapidly disappear from the 

 blood. (2) The reason of this fact is not that they are destroyed, 

 but that they are detained in some of the parenchymatous organs. 



(3) When the subject survives the operation more than three days, 

 they disappear even from the organs mentioned, and health is restored. 



(4) To the unsuitability of the organization of such animals for the 

 growth of the bacterium the surface of the brain is a marked excep- 

 tion, but the growth in this case has characters never observed in 

 living animals attacked by true splenic fever. These characters are, 

 however, presented by the bacteria of cultivating solutions, and, under 

 certain conditions, in blood of animals after death. 



