348 ANTHRAX 



as of special frequency in strains deprived of their power of 

 sporulation by heat, and different colonies isolated from such 

 strains may present differences in the character of the capsule. 

 There is a general opinion that capacity to produce a well-formed 

 firm capsule is associated with the possession of special 

 virulence, non-capsulating strains frequently showing low 

 pathogenic qualities. According to Ottolenghi, in cultures the 

 capsule is formed from the carbo-hydrates present. 



It is evident from what has been said that modifications in 

 both biological and cultural characters can be artificially 

 originated in anthrax bacilli. These observations are important 

 in relation to the fact that from material where the anthrax 

 bacillus might be present, organisms closely resembling it have 

 been isolated, the differences relating to details in the appearance 

 of cultures and to variations in pathogenic properties. The 

 problem thus arises whether these are to be looked on as modi- 

 fications of the true anthrax bacillus or whether, as with other 

 organisms, there exists in nature a group of closely allied 

 bacteria. 



Anthrax in Animals. Anthrax occurs from time to time 

 epidemically in sheep, cattle, and, more rarely, in horses and 

 deer. These epidemics are found in various parts of the world, 

 although they are naturally most far-reaching where legal pre- 

 cautions to prevent the spread of infection are non-existent. 

 All the countries of Europe are from time to time visited by the 

 disease, but in some it is much more common than in others. 

 In Britain the death-rate is small, and apparently often only one 

 animal in a herd is affected, but in France the annual mortality 

 among sheep was probably 10 per cent, of the total number in 

 the country, and among cattle 5 per cent. These figures, how- 

 ever, have been largely modified by the system of preventive 

 treatment which will be presently described. In sheep and 

 cattle the disease is specially virulent. An animal may suddenly 

 drop down, with symptoms of collapse, quickening of pulse and 

 respiration, and dyspnoea, and death may occur in a few 

 minutes. In less acute cases the animal is apparently out of 

 sorts, and does not feed ; its pulse and respiration are quickened ; 

 rigors occur, succeeded by high temperature ; there is a 

 sanguineous discharge from the bowels, and bloody mucus may 

 be observed about the mouth and nose. There may be con- 

 vulsive movements, and progressive weakness, with cyanosis, 

 is followed by death in from twelve to forty-eight hours. In 

 the more prolonged cases widespread oedema and extensive 

 enlargement of lymphatic glands are marked features ; and in 



