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 tins 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, Z. elegans, and Z. paniculatus have 
ordinarily the same degree of toxicity wherever grown, there is a pos- 
sibility of marked variation. 
