30 
The Bulletin 
TABLE I— Results of Feeding White Snakeroot to Sheep in 1916. Experiment 3. 
Ewe 
Initial 
Experiment 
Feeding 
Days before 
Weight 
Feed consumed 
No. 
weight. 
begun. 
discontinued. 
death occurred. 
at death. 
Grain 
Weed 
Pounds. 
Pounds 
Pounds. 
Pounds. 
12 
74 
August 5 
August 18 
13* 
5.5 
11.5 
7 
86 
August 5 
September 1 
27 
61 
13 
9 
29 
81 
August 5 
August 21 
16 
55 
8 
10 
27 
70 
August 5 
August 10 
5 
56 
2.25 
4.5 
19 
113 
August 5 
August 23 
18 
89 
8 
11.25 
*Feeding discontinued after thirteen days. 
Ewe 12 was taken off the experiment on August 18, at which time 
she was affected with trembles. She had lost only 1 pound during these 
13 days. It will be noted that the amount of weed required to cause 
trembles in these five animals varied from 4% to 11% pounds and the 
range in time from 5 to 27 days. 
Experiment A—In order to determine whether or not trembles is 
infectious, ewes 26 and 12 were put in a small Bermuda grass lot on 
August 18. Two healthy ewes from the flock were put in the same lot 
and all were fed grain in the same trough. It will be recalled that 
both ewe 26 and ewe 12 had typical cases of trembles when their feeding 
in experiments 2 and 3, respectively, were discontinued. Ewe 26 died 
on August 19 and ewe 12 still trembled a week afterward. However, 
she finally recovered fully. Neither of the other two ewes had devel¬ 
oped any symptom of trembles when the experiment was discontinued 
on September 4, and both subsequently remained normal. It is real¬ 
ized that this indirect evidence of the relationship of a specific infec¬ 
tion is in itself not convincing so that in studies to be subsequently re¬ 
ported an effort was made to isolate an organism from the internal 
organs of affected animals. 
Experiment 5 .—This experiment was designed to determine the length 
of time that white snakeroot must be fed to sheep when, after a certain 
number of days the usual grain ration and pasturage are given. Two 
animals were therefore fed for three days on a mixture of equal parts of 
ground weed and grain and were then put on pasture. Two others were 
fed for six days before being placed on pasture and two others for 
nine days, after which they were put on pasture. Table II contains the 
essential facts in this experiment. 
