34 



STOCK-POISONING PLANTS OF MONTANA. 



exchif^ively upon the native grasses on the range. It should be stated 

 that these grasses Avere in excellent condition at the time and the 

 sheep were by no means forced to eat other plants. It may be of 

 interest to note also that no sheep were observed eating the smaller 

 species of larkspur, although this plant grew in great abundance on 

 the range where the}' were feeding. 



Not only are striking differences to t)e observed in the feeding habits 

 of individual sheep in a given band and in different bands in different 

 parts of the State during one season, but a considerat)le variation is to 

 be o])served in different years on the same range. In many parts of 

 the State the death camas and the small larkspur grow in the same 

 locations, and they are both in their most tempting condition at the 

 same time. Cases of poisoning which occur where both are present 

 are easil}' traceable entirel}' to one or the other of these plants. Dur- 

 ing some years death camas is eaten, while during other years the 

 poisoning is traceable to the larkspur. It is difficult to discover the 

 cause of this variation in the appetite of the sheep. Their arbitrary 

 selection of one plant at one time and another at another time is one 

 of the chief factors in determining the amount of poisoning which 

 will occur on a given range during any particular season. It is the 

 only factor which can not be estimated in any definite manner. It is 

 a comparatively simple matter for the liotanist to determine what poi- 

 sonous plants grow on the particular range and to indicate their rela- 

 tive alnmdance or scarcity. It is possible to determine by feeding 

 experiments the amount of any particular plant which must be eaten 

 in order to cause death, but no one can with certainty predict whether 

 a given band of sheep will eat any particular poisonous plant when 

 allowed to graze on the range where that plant grows. 



EXTENT OF STOCK POISONING. 



In order to give an idea of the importance of the general subject of 

 plant poisoning to the stock industry, the cases which came under our 

 observation during the season of 1900 due to the more important poi- 

 sonous plants are here tabulated. The number of fatal cases is indi- 

 cated in each case. Probably only about one-fourth of the actual 

 cases came under our notice. 



Pom)inng cases aniony cattle, horsex, and sheej) in Montaiia obsirredduriiiy tlw season >ij' IMO. 



