MEXICAN WHOELED MILKWEED AS A POISONOUS PLANT. 
DURATION OF SICKNESS. 
Table 3 shows the length of time the sickness continued in cases 
which recovered. The times were computed from the first symtom 
noted to the last. The actual periods of illness doubtless were some- 
what greater, for as the animals were not generally under constant 
observation neither the beginning nor the ending of sickness would 
be recorded with much accuracy. The figures, however, will give a 
good general idea of the duration of illness and can be compared 
with the results in the other whorled milkweeds, as they were obtained 
in the same manner. 
Table 3. — Duration of sickness in cases of recovery. 
Animal. 
Sheep 588 . 
Sheep 595. 
Sheep 603 . 
Sheep 581 . 
Sheep 586. 
Duration 
of symp- 
toms. 
H. 
m. 
50 
10 
48 
20 
48 
1 
7 
30 
7 
54 
Animal. 
Duration 
1 or symp- 
I toms. 
Sheep 568 . 
Sheep 575 . 
Sheep 580. 
Sheep 602 . 
Sheep 603. 
H. m. 
95 54 
73 45 
74 6 
5 40 
0) 
1 One observation only. 
Of the three animals that died, Sheep 610 was sick 89 hours and 
35 minutes; Sheep 596, 14 hours and 56 minutes; and Sheep 595, 
15 hours and 15 minutes. 
The shortest period of illness was in Sheep 602 — 5 hours and 40 
minutes — and the longest in Sheep 568 — 95 hours and 54 minutes. 
As in other whorled-milkweed cases the symptoms continued longest 
in the more pronounced cases. 
The average period of sickness was 45 hours and 42 minutes. 
It was shown in Bulletin 942, United States Department of Agri- 
culture, pages 12-13, that the average period of sickness in sheep 
poisoned by A. galioides was 4 hours and 39 minutes; by A. pumila 
it was 48 hours; and by A. verticillata var. geyeri it was 56 hours. 
It is evident that the period of sickness in the A. mexicana cases 
corresponded fairly well to that found for A. pumila and A. verti- 
cillata var. geyeri, and like them differed widely from the A. galioides 
cases. 
In the experiments of Fleming and co-authors (1920) the average 
duration of sickness in the sheep that recovered, as given in Tables I, 
II, and III, was 39 hours and 37 minutes, while in the cattle as 
given in Tables VII and IX it was 34 hours and 1 minute. 
AUTOPSY FINDINGS. 
Autopsies were made upon the three animals that died. Two of 
the three were bloated. The lungs were congested in all. In 
two the thymus was congested, and in the third there were petechia? 
in this organ. Petechia? were present on the hearts of two. 
