INFECTION. 109 



strated not only the presence of the bacteria in the blood of the 

 mother, and their absence in that of the foetus, but also that, while 

 the blood of the mother was highly infections, that of the foetus 

 was wanting in this quality. 



This only goes to prove that in this case, even if the micrococci, 

 or germ condition of the bacteria, be present in the mother, it is 

 not so in the foetus ; but does not militate against the proved fact 

 that blood from anthrax-diseased animals without bacteria is still 

 infectious. 



Feser has made some interesting experiments with regard to 

 the filtering ability of the milk-glands in sheep. He has inocu- 

 lated ewes with lambs by their side, and proved that infection had 

 taken place, both by examination of the blood and by experiments 

 with the same upon other animals ; but the lambs did not become 

 infected from the mother's milk, although isolated bacteria were to 

 be seen in the same. Inoculations made with such milk, however, 

 produced the disease in other animals. 



The presence of the bacteria in the milk, and its infectiousness 

 on inoculation, while the lambs feeding upon it were not infected) 

 go to support a theory of infection we have already considered in 

 our general remarks, viz., that a wounded or abraded surface is ne- 

 cessary to the infection of an organism. In lambs feeding upon 

 milk alone such is surely impossible in the course of the digestive 

 tract. 



The fact that bacteria pass the membranes of the milk-glands 

 and not those of the placenta, may be explained by the mechanical 

 action and minor lesions, which can result to the milk-glands from 

 the sucking and butting of the lambs. 



As we have frequently mentioned, this disease is now known to 

 be due to a specific cause — a schizophyte, or vegetable parasite, 

 bacillus anthracis — a staff-shaped bacterium which multiplies by 

 spores. 



An English observer, Ewart, of University College, London, 

 gives a very clear description of the life of these germs, which may 

 not be out of place here, notwithstanding all we have previously 

 considered : 



" At first the bacilli were absolutely motionless — they had been 

 taken from the spleen of a mouse — but in some cultivations, after 

 keeping them in a temperature of 33° C. for a few hours, a great 

 number of them began to move actively about the field. "While 

 at rest they were not altogether without change, for clear lines 

 across them indicated that they were in the process of division 



