12 BULLETIN 942, U. S. DEPARTMENT OF AGRICULTURE. 



TIME REQUIRED TO PRODUCE SYMPTOMS. 



The following table shows the time that elapsed between the giv- 

 ing of the plant and the appearance of symptoms : 



Table 6. — Time elapsed after feeding A. verticillata var. geyeri before appear- 

 ance of symptoms. 



Animal. 



Quantity 

 fed per 



100 

 pounds 

 of ani- 

 mal. 



Result. 



Time elapsed 



before 



symptoms 



appeared. 



Sheep 473 

 Sheep 4S2 

 Sheep 523 



Pounds. 

 2.205 

 1.286 

 1.47 



Very sick 



Sick 



....do.... 



Hrs. Mins 



14 10 



15 35 

 20 35 



The average time before symptoms appeared was 16 hours 47 

 minutes. As noted on page 6, this time, in the case of Asclepias 

 pumila, was 16 hours and 17 minutes. In Bulletin 800, United States 

 Department of Agriculture, page 34, it was shown that in the Ascle- 

 pias galioides cases the average elapsed time was 14.1 hours. It is 

 evident that in respect to the time elapsing between the feeding and 

 the development of symptoms, the three species are practically alike. 



CONTINUATION OF SYMPTOMS. 



As in A. pumila cases, the symptoms persisted for a considerable 

 length of time after their first appearance. 



In Sheep 473, symptoms continued 4 days. 

 In Sheep 482, symptoms continued 2 days. 

 In Sheep 523, symptoms continued 1 day. 

 Sheep 473 was the only animal seriously affected, and the symptoms 

 continued much longer than in the others. 



COMPARISON OF DURATION OF SYMPTOMS IN A. PUMILA, A. VERTICILLATA VAR. GEYERI, 



AND A. GALIOIDES. 



The following statement shows the time during which symptoms 

 persisted in the A. galioides cases : 



Horse 126, symptoms continued 6 days. 



Cattle 750, symptoms continued 1J days. 



Sheep 478, symptoms continued 6 hours. 



Sheep 506, symptoms continued 3 hours. 



Sheep 534, symptoms continued 1 hour. 



Sheep 542, symptoms continued 4 hours. 



Sheep 372, symptoms continued 11 hours. 



Sheep 522, symptoms continued (September 11) 3£ hours. 



Sheep 522, symptoms continued (September 22) 4 hours. 



For comparative purposes the horse and cow may be disregarded. 

 In fact, the horse never completely recovered, although the immediate 

 symptoms of the sickness disappeared. 



