26 
It is quite common to find the loco, that was abundant in 
a certain locality one year, the next year to be nearly all 
gone. This is no doubt due to the ravages of insect parasites. 
We examined the root and found a larvae or grub of Tinei- 
dcE. Prof. Riley’s letter shows the leaves may contain a 
weevil, BrucJius, and we have seen a great many snout-beet¬ 
les, curculionid, on the plants. Coulter’s manual of The 
Rocky Mountain Region gives under Astragalus 64 kinds, 
and under Oxytropis 11 kinds, making 75 kinds of the so called 
loco weeds. The figures of the loco weeds were drawn from 
nature by Miss Minnie Harrington, a student of the College. 
During the past year my assissant, Mr. Ryan, helped me in 
the chemical examination of the plants, and in confirming 
the tests of former years. 
CONCLUSION. 
In conclusion we would say we have been unable to find 
any alkaloid in the plants examined, though we get alkaloidal 
reactions from the loco and the alfalfa. 
We have not been able to produce any physiological ac¬ 
tion upon rabbits with the extract from the loco in any of its 
forms. In the case of the sheep in the southern part of the 
state, said to have been locoed, it has long been known that 
the disease was caused by parasites in the liver. 
The post mortems made showed such a variety of dis¬ 
eased conditions that in our judgment they could hardly be 
due to one or the same cause. 
It has always been noticed that when the feed on the 
range is good, locoed animals are scarce. The range about 
Fort Collins contains the loco in large quantities, but I have 
never seen a locoed animal except upon the mountain range 
or foothills. 
In our experience the animals affected, and the subjects 
for post mortems, were in every case young animals, mostly 
under four years old, the great majority yearlings and two 
year olds, 
I have long been persuaded that the person who investi¬ 
gates the subject of loco should spend considerable of his 
time on the range and notice very carefully the habits of the 
animals, the food they eat, and the water they drink. The 
subject has not been investigated to the extent that its im¬ 
portance demands. 
It is never wise to draw hasty conclusions from imper¬ 
fect data, or from a few post mortems. Judgment had 
better be withheld until the subject is more thoroughly in¬ 
vestigated. 
