POISONS. 187 



minute quantities as to cause nothing more than 

 a slight discomfort. 



Old stockmen regard plant poisoning as prevent- 

 able diseases. Their young herders often grow 

 impatient to be off for the range, but the older 

 heads look wise and say nothing, and remain in 

 winter quarters. When first starting out in the 

 spring, the "old man" will ride ahead and care- 

 fully peer over the grazing ground on the lookout 

 for "pizen." 



As Glover of Colorado has well said, ' ' Through- 

 out the vegetable kingdom, from bacteria to the 

 mighty oak, we find species of plants poisonous 

 under certain conditions, but few of them poison- 

 ous under all conditions. " This is further illus- 

 trated by the following statements: 



1. Some plants are poisonous only at certain 

 stages of growth ; for example, the lupine is poison- 

 ous at the time of going to seed; larkspur loses its 

 toxic properties at flowering time; death camas 

 is very deadly in the early spring, but later 

 dries up. 



2. Unusual conditions and ecological factors 

 may affect the quantity of poison in plants. The 

 wilted leaves of the wild cherry or choke cherry 

 are poisonous. 



3. Poison is found in different parts of the 

 plant, such as in the roots of wild parsnips, the 

 seeds of lupine, the leaves of the wild or choke 

 cherry, and the entire plant of death camas and 

 aconite. 



4. Variations occur owing to season and 



