CIECUM6TANCES AFFECTING DANGER OF POISONING. 29 



INFLUENCE OF THE STATE OF VEGETATION. 



The state of the sum total of the local vegetation as affected Vjy 

 seasonal and special weather conditions ordinarily exercises consider- 

 able influence on the occurrence or nonoccurrence of poisoning. In 

 the early spring certain poisonous plants may start to grow before the 

 native grasses. In this case, if these poisonous plants are at all con- 

 spicuous or offer an}- considerable amount of succulent material, stock 

 are apt to be tempted to eat them. The acrid, bitter, or otherwise dis- 

 agreeable taste of such plants seems to have very little influence in 

 preventing stock from eating them. Under the conditions which have 

 just been outlined sheep and cattle eat large quantities of various 

 plants which are extremely unpalatable to the human taste. Later in 

 the season, when grasses and other plants are all in vigorous vegeta- 

 tive growth, it often happens that poisonous plants are eaten along 

 with grasses because of their resemblance to grass, as in the case of 

 Zy go den an (death camas), or because of their dark-green and tempt- 

 ing appearance, as in the case of larkspur and water hemlock. 



In seasons of unusual drought the native grasses on the range 

 usually mature earlv in the season. In such cases a number of other 

 plants frequently remain green and tempting to the stock after the 

 grasses have become thoroughly dried. This is especially true of a 

 number of native leguminous plants, among which are several valuable 

 forage plants and some poisonous ones, such as the loco and lupine. 

 In times of drought, accordingly, these plants, including the injurious 

 -species, are eaten by stock to a much greater extent than when grass 

 is in a green, normal condition. It was noticed that young lambs 

 when first beginning to eat were especially liable to acquire the habit 

 of eating loco weeds when the native grasses were badly dried up. 

 The same statement may be made of older sheep, with the qualification 

 that thoy are affected in a less degree. In general, it mav be stated 

 as being obviously true that stock will be more apt to eat poisonous 

 plants when such plants offer more tempting forage than the grass. 

 The converse of this statement is also obviously clear that when 

 grasses and other harmless forage plants are present in abundance and 

 in good condition sheep and cattle less often make the mistake of eat- 

 ing poisonous plants. 



INFLUENCK OK THE STAdE OF GROWTH OF PLANTS. 



The actual stage of growth of any poisonous plant determines veiy 

 largely whether or not it is eaten at a given time. Some of the pois- 

 onous plants — as, for instance, the taller species of larkspur and water 

 hemlock — become so large and coarse during their later stages that 

 they are seldom if ever eaten b}- sheep in that condition. On the 



