108 STOCK-POISONING PLANTS OF MONTANA. 



had been eaten was sufficient to cause the death of so manj'^ sheep, 

 with a death rate of 63 per cent, nor account for the fact that onl}^ one 

 baud of sheep was poisoned while the other remained entirely 

 unharmed. Yet post-mortem examinations, made on a number of 

 sheep, one of which had just died, revealed large quantities of lupine 

 pods and seeds in nearly every stomach, and no evidence of any other 

 poisonous substance was to be found. The results of the first exami- 

 nations were confirmed by a second visit to this locality several days 

 later for the purpose of making further examination of the stomach 

 contents. Large numbers of carcasses still lay on the ground in a 

 badly decomposed condition, but it was a comparativeh^ easj^ matter 

 to demonstrate the presence of lupine pods in every stomach. About 

 75 sheep were examined for this purpose. The fact that lupine pods 

 are exceedingly hard and resist decomposition for weeks, combined 

 with their characteristic shape, makes their identification a very easy 

 matter. 



Further facts were developed, however, which furnished a satisfac- 

 tory explanation. A large quantit}^ of lupine grew on the side of the 

 creek where the band which was poisoned camped for the night, 

 while on the other side of the creek where the other band camped no 

 lupine was found. The first band was driven across the creek about 

 8 o'clock in the evening and grazed for some time before lying down. 

 They thus had opportunity to eat the lupine which grew on that side 

 of the creek, and an examination of this lupine showed that the pods 

 had been stripped ofl^. 



The immunit)^ of the second band is explained by the fact that with 

 the exception of the first mile of the drive, this band took a course 

 different from that of the first band, though parallel with it. No 

 lupine grew on the first mile of the drive where both bands followed 

 the same course, and it so happened that the course of the second band 

 for the rest of the distance led through fields where no lupine was to 

 be found. The most abundant plant along this course was Astragalus 

 drummondii^ a good forage plant, of which the pods had been eaten 

 extensively by the sheep. While the first band of sheep, therefore, 

 had opportunit}' to eat the lupine, not only near its camping ground 

 but at several other points along the course of the drive, the second 

 band had no opportunity of eating it. At one point in the course of 

 the drive, indeed, all the sheep passed through a small area of another 

 species of lupine (Z. psefadoparvijiorus)^ but this species had formed 

 scarcely any pods and was not eaten b}^ the sheep. 



EXPERIMENT. 



On June 26 two sheep were fed each 150 medium-sized lupine pods 

 which were well filled with nearly ripe seeds. The sheep ate the pods 

 readily and seemed to manifest a fondness for them. Both sheep 

 became frenzied in about forty-five minutes after eating the lupine 



