86 PASTURE AND RANGE. 



There are few American plants whose poisonous prop- 

 erties have caused so much controversy as those of 

 T h] White Snakeroot. The disease called "trem- 



Milksickness bles," which has lately been conclusively 

 traced to it, was for many years a mystery. 

 The trouble was formerly prevalent among animals feed- 

 ing- in wooded pastures, affecting more especially cattle 

 and sheep, particularly in some of the eastern and central 

 United States. It was variously attributed to bacteria, to 

 a poison in the soil, to exhalations from the swamps, and 

 to the bites of insects or small arthropods. Farmers 

 learned that if they fenced their cattle away from the 

 woods and swamps the disease did not trouble them. The 

 serious character of the disease was increased by the fact 

 that it was communicated to human beings by the milk 

 of animals suffering from it. People who acquired it 

 rarely recovered, and those who did survive were victims 

 of permanent nervous debility. The fact of its communi- 

 cation by means of milk led to the application of the 

 name "milksickness" to the disease. 



The symptoms usually develop when cattle are out in 



pasture. Some stockmen believe that the disease is more 



prevalent in autumn. This may be due 



, or , partly to the fact that unusual exercise and 

 Development of * 



Disease excitement hasten the development and in- 



crease the intensity of the symptoms, so 

 that the disease becomes more apparent at the time when 

 stock is being driven to market. The scarcity of other 

 pasture at this season would also lead to the ingestion 

 of larger amounts of the plant. In rare cases animals are 

 attacked in winter, when, according to experienced stock- 

 men, the disease comes as a result of the feeding of 

 swamp hay. This fact is significant, as such hay is the 

 only winter feed likely to contain White Snakeroot. 



