APM a 
DEATH CAMAS SPECIES, ZYGADENUS PANICULATUS. ts 
cases the duration of illness was correlated with the severity of the 
attack. 
Of the cattle it should be noted that on 874 and 861 only a single 
observation was made, so that the sickness can not be considered as 
continuing an appreciable length of time. Of the other cattle, the 
average time of duration of illness was 57 hours and 7 minutes, while 
the shortest period was 30 minutes, and the longest 4 days. 
TIME REQUIRED TO PRODUCE SYMPTOMS. 
‘The cattle and two of the sheep were given the Zygadenus in hay, 
so that the feeding extended over a considerable period of time, and 
it would be impossible in these cases to determine the time between 
the feeding and the appearance of symptoms. This can be done, 
however, in the animals that were given a forced feeding by the balling 
gun.. The following table shows the time elapsed in the case of 
these sheep. 
TaBLE 3.—Time elapsed between feeding of plant and development of symptoms. 
Time elapsed Time elapsed Time elapsed 
Animal. before symp- Animal. before symp- | Animal. before symp- 
= toms appeared. | toms appeared. toms appeared. 
1919. | 1920. | 1921. 
Sheep Nos.: Sheep Nos.: | Sheep Nos.: 
FD s a Beare 3 hours. BOS ae 5 hours 30 minutes.|| ’ DS Qu eae 4 hours. 
Be oe od 1 hour 47 minutes. 9992 F522 3 hours. | GL Qe ees | 4 hours 44 minutes. 
DOO 2 hours 33 minutes. G02F er: Do. Chae 2 hours 5 minutes. 
ADE aa: -.| 2 hours 12 minutes. €09......| 55 minutes. | 6287S 50 minutes. 
GOMES 3 hrs. | 629: 1 hour 38 minutes. 
1920. DOQE as 2 hours 15 minutes. |) 644..... 1 hours 42 minutes. 
Sheep Nos.: | _ NGessace 4 hours 30 minutes. | OCLs 2 hours 2 minutes. 
eo ee eoae 22 hours 7 minutes. 609..:...| 8 hours 40 minutes. |) 
OU eee 3 hours. Sones 2 hrs. | 
The time elapsing varied between 50 minutes in the case of Sheep 
628, and 22 hours and 7 minutes in the case of the first experiment 
with Sheep 583. In this case, however, it is probable that the time 
is very much too long, because no observation was made upon the 
animal from 4.47 p. m., June 21, to 9.22 a.m., June 22. It is to be 
presumed that the animal was sick during the night. Excluding this 
animal, the maximum time elapsing was 8 hours and 40 minutes, in 
the second poisoning case of Sheep 609. Excluding, too, the case 
of Sheep 583, the average of all these sheep cases was 2 hours and 58 
minutes. 
TOXIC AND LETHAL DOSAGE. 
It is evident that a number of factors may affect the toxic dosage 
of any plant. Most prominent among these factors are the method 
of feeding, the age of the plant, the part of the plant used, and the 
kind of animal used for experimental purposes. Any figures in regard 
to dosage may have a considerable margin of error, as very few 
animals are subject to experiment under exactly the same conditions. 
