DEATH CAMAS SPECIES, ZYGADENUS PANICULATITS. 



13 



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.: 





i Sheep Nos.: 





528 



3 hours. 



593 



5 hours 30 minutes. 



582 



4 hours. 



530 



1 hour 47 minutes. 



599 



3 hours. 



612 



4 hours 44 minutes. 



555 



2 hours 33 minutes. 



602 



Do. 



617 



2 hours 5 minutes. 



540 



2 hours 12 minutes. 



609 



55 minutes. 



628 



50 minutes. 







609 



3hrs. 



629 



1 hour 38 minutes. 



1920. 





569 



2 hours 15 minutes. 



644 



1 hours 42 minutes. 



Sheep Nos.: 





575 



4 hours 30 minutes. 



647 



2 hours 2 minutes. 



583 



22 hours 7 minutes. 



609 



8 hours 40 minutes. 







590 



3 hours. 



583 



2hrs. 



. 





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. 



