DEATH CAMAS SPECIES, ZYGADENUS PANICULATUS. 15 



few cases over 1 pound has been fed with negative results. Sheep 

 most frequently have been made sick with amounts in excess of 1 

 pound, while most of the deaths have resulted from If to 4 pound 

 feedings. Fleming does not give the weights of the animals. If it 

 is assumed, however, that his sheep weighed 100 pounds each, his 

 figures for sheep would not differ widely from those obtained by us. 

 If his yearling calves were well grown, his figures for cattle would be 

 much smaller than those in this paper. In any case, he seems to 

 have found the plant much more toxic for cattle than for sheep, 

 thus far confirming the apparent result of the work reported here. 



Toxic dose of Z. paniculatus compared with Z. gramineus. — It is diffi- 

 cult to make anything like an exact comparison of the present results 

 with those given in Bulletin 125 for Z. gramineus, because the experi- 

 ments on Z. gramineus were not very carefully checked up with 

 regard to loss of moisture. The Z. gramineus, however, was ordi- 

 narily used fresh, so that this difference is not so great as it otherwise 

 would be. In the case of Z. paniculatus, as quoted in the bulletin, 

 the material used was several days old, and without doubt the dosage 

 would be multiplied by four to bring the figures to green weight. 

 As compared with Z. gramineus, the seeds and fruit heads of Z. 

 paniculatus are fully as toxic, but the other parts of the plant are 

 much less toxic. The work with Z. gramineus showed that in a 

 general way the toxic dose was about 0.5 pound, while the work 

 with Z. paniculatus, as stated above, indicates that in a general way 

 the toxic dose is between 1 and 2 pounds, or it may be said that Z. 

 gramineus is approximately three times as poisonous as Z. pani- 

 culatus. 



Lethal dosage. — Only one death occurred during the experimental 

 work with Z. paniculatus, that of Sheep 644, on 2.5 pounds, and this 

 animal suffered from pneumonia. That it will and does kill under 

 range conditions, however, is abundantly proved by many well- 

 authenticated cases. 



LOSSES FROM Z. PANICULATUS. 



The stockmen, of course, make no distinction between the species 

 of death camas. Moreover, the systematic botanists are by no means 

 agreed as to the determination of species or the names which should 

 be applied to them. This confusion makes it difficult to state defi- 

 nitely whether reported losses from death camas should be ascribed 

 to one species rather than another. From the distribution of Z. 

 paniculatus, as given on page 3, it may be assumed that most of the 

 death-camas losses in Utah, Nevada, Idaho, and eastern Oregon are 

 caused by this species. These losses have been very heavy. 



