STATE HYGIENE 591 



material may suffice. It may be said that this is probably 

 the only way in which cattle may be infected — viz., some 

 wound which admits of the organisms in the earth pene- 

 trating into the subcutaneous tissues. 



From this it may be judged that the disease does not 

 spread from animal to animal in the sense in which this is 

 usually understood. 



The animals principally affected by quarter-evil are oxen 

 and sheep, the former particularly. Age has an important 

 influence in cattle ; under two years old the disease is 

 common, over that age it is rare. The influence of age is 

 not seen in the case of sheep. Calves still suckling are 

 generally considered to be immune, but McFadyean,* whose 

 views are here being represented, says that experimental 

 inquiry does not bear this out. 



The commonly assigned predisposing causes of the 

 disease are rapid growth, excess of blood, forced feeding, or 

 even the converse poverty of blood ; but McFadyean rejects 

 all these on the basis of insufficient evidence, and mentions 

 that some experienced observers have held that liberal feed- 

 ing reduces the mortality from the disease. 



The mortality from quarter-evil is excessive, practically 

 none recover, and death may occur within two or three 

 hours of the attack, while with sheep it is still more 

 rapidly fatal. 



There is no putrefaction in the crackling tumour during 

 life, but the carcases rapidly putrify after death, and the 

 organism which produces the disease, unlike that of 

 anthrax, is not destroyed by the putrefactive change. 



For many years the setoning of calves in the dewlap as 

 a protection against quarter-evil has been practised, espe- 

 cially on quarter-evil farms where infection occurs year by 

 year.t The scientific value of this measure is unknown, 



* ' Quarter-Evil ' : Journal of the Boyal Agricultural Society, 

 vol. ix., part iv., 1898. 



t Quarter-evil lands have a very unequal distribution. There are 

 whole counties in which the disease hardly ever occurs, and others in 

 which it is only too common. Some farms may be badly affected, 



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