xii.] Anthrax. 125 



up to the moment of death. In many instances I observed 

 guinea-pigs lively and eager for food, till they all at once (about 

 forty-eight hours after infection) collapsed and died after a short 

 struggle. 



If a diseased animal is examined a little before or immediately 

 after death, the vegetative rods of Bacillus Anthracis (Fig. 17, c) 

 are found in its blood. In larger animals, such as horned 

 cattle, their numbers appear from the accounts before us to vary 

 in every case. I say appear for reasons to be given presently. 

 But they are always found in the capillaries of the internal 

 organs, at least in the spleen. Koch states that they are not 

 numerous in the blood of rabbits and mice, but are all the more 

 numerous in the lymphatic glands and in the spleen. In guinea- 

 pigs, the animals which I have myself chiefly examined, the 

 entire mass of the blood is permeated by the rods ; the smallest 

 drop of blood, scarcely visible to the naked eye, taken from a 

 slight puncture in the ear, or toe, or elsewhere, contains them ; 

 they are present in enormous numbers in the small vessels and 

 capillaries of the liver, kidneys, spleen, and other organs. The 

 same state of things continues for some time also after death ; 

 at a later period, when the first rigidity of death is passed away 

 it often changes visibly, and it is possible to obtain considerable 

 quantities of blood from the large blood-vessels, or from the 

 heart of the animal without discovering a single rod in them. 

 The rods are there but they are inclosed, often in large numbers, 

 in the clots of fibrin, which it may be said in passing will supply 

 the purest material for the culture of the Bacillus. It is quite 

 possible that in the cases in which few rods were observed, the 

 reason was, that those which were inclosed in the clots of fibrin 

 were overlooked when the dead animal was examined after the 

 coagulation of the blood ; this is a point to be remembered in 

 connection with the statements mentioned above, that the Bacilli 

 are present sometimes in larger sometimes in smaller quantities. 



The rods were first seen by Rayer in 1850, and next by 

 Pollender, independently of Rayer, in 1855. The causal con- 



