36 BULLETIN 125, U. S. DEPARTMENT OF AGRICULTURE. 



was also used from Avery, Cal., collected at an elevation of 3,500 feet. 

 The material of Z. elegans was from two localities, from near Red 

 Lodge, Mont., at an elevation between 5,500 and 6,000 feet, and from 

 the Fishlake National Forest, Utah, at an elevation of something 

 over 9,000 feet. The Z. paniculatus material was collected near 

 Ephraim, Utah, at an elevation between 5,500 and 6,000 feet. All 

 the Z. coloradensis material was collected within 4 or 5 miles of the 

 Mount Carbon station, at an elevation of something over 10,000 feet. 



As has been stated already, the lack of toxic properties in Zygadenus 

 coloradensis is assumed to be characteristic of the species. The experi- 

 ments with Z. elegans and Z. paniculatus were few in number, and 

 too much importance must not be attached to the results. Appar- 

 ently, however, not only did they have, practically, the same toxicity 

 as the Z. venenosus collected near the station, but there was no evident 

 difference between the Z. elegans of Montana and that collected in 

 Utah. The Z. venenosus, collected in California gave the same results 

 as that produced by material from the neighborhood of the Greycliff 

 station. 



An entirely unexplained variation in toxicity was exhibited by 

 material collected at Cabin Corral, about 5 miles from the station and 

 at a greater elevation of about a thousand feet. When Table II 

 was being compiled, it was noticed that the cases receiving "forced 

 feeding of leaves stems, flowers, and buds" fell into two distinct 

 divisions, one with an average dosage of 0.5495 pound and the other 

 with an average of 1.789 pounds. This difference was so marked 

 that the two sets were separated in the summary. In searching for 

 some possible explanation of this difference, it was found that all 

 the cases with the larger dosage were treated with material collected 

 at Cabin Corral. Note was then made of the other items in this table 

 which were collected in this locality, and a glance at the table will 

 show that in the other cases the Cabin-Corral material showed much 

 less toxicity. It has been entirely impossible to explain this difference. 

 The number of cases would seem to make it certain that this result 

 was not due to an error of experimentation. There are no local 

 conditions to account for it. The George Hughes place, at which 

 collections were made giving the same results as those produced by 

 the station material, is situated at about the same distance from the 

 camp as Cabin Corral, at about the same elevation, and it has the 

 same soil conditions. The question of the correlation of variation 

 in toxicity with changes in altitude was raised, but the experiments do 

 not indicate any such relation. The fact that the Cabin-Corral mate- 

 rial was less toxic is nevertheless substantiated, and it would appear 

 that while Zygadenus venenosus f Z. elegans y and Z. paniculatus have 

 ordinarily the same degree of toxicity wherever grown, there is a pos- 

 sibility of marked variation. 



