LARKSPUR POISONING OF LIVE STOCK. 85 
during one season at Greycliff, Mont., on Delphinium cucullatum 
and D. bicolor. 
4. These experiment* showed that the larkspurs are poisonous to 
cattle and horses but not to sheep. Horses, however, in pastures or 
upon the range do not eat enough of the plants to produce any ill 
effects, so that losses of stock from larkspur poisoning are confined 
to cattle. 
5. The low larkspurs are poisonous during the whole life of the 
plants, but inasmuch as they disappear early in July, cases of poison- 
ing are confined to the months of May and June. 
6. The tall larkspurs live through the summer season, appearing 
in early spring. They are most poisonous in their early stages. After 
blossoming the toxicity gradually diminishes and disappears and the 
plant dries up, although the seeds are very toxic. Most of the cases 
of poisoning in Colorado occur in May and June, with sporadic 
cases in July. In other localities where the larkspurs blossom later 
poisoning may occur as late as August or even September. 
7. While definite feeding experiments have been performed upon 
only a few species of larkspur, it may be assumed, from the knowledge 
of plant poisoning upon the ranges, that other species have the same 
properties as those experimented upon and that feeding upon them 
produces the same results. 
8. The experimental work and the autopsies showed a clearly de- 
fined line of symptoms and certain definite pathological results. 
9. The feeding showed that there was no marked difference in 
toxicity between the different species of larkspurs and that the quan- 
tity necessary to produce effects varied within rather wide limits, but 
that, generally speaking, a quantity equal to at least 3 per cent of the 
weight of the animal was necessary to produce poisoning. 
10. From somewhat extensive experimental work on antidotes it 
was found that beneficial results could be obtained by using, hypo- 
dermically, injections of physostigmin salicylate, pilocarpin hydro- 
chlorid, and strychnin sulphate, followed by hypodermic injections 
of whisky when needed. 
11. Poisoning upon the range may be prevented in some cases by 
digging up the tall larkspur when the greater number of plants is 
confined to comparatively limited areas. In other cases the handling 
of the cattle in sucn a way that they will not have an opportunity to 
feed upon the larkspur may prevent losses. In the case of Del- 
phinium menziesii it is desirable that the cattle should be kept away 
from the ranges where this plant grows in abundance until about the 
1st of July, when the plant dies. D. harbeyi loses its toxicity after 
blossoming, so that a range with this plant is safe for cattle in the 
late summer and fall. It should be remembered, however, that local 
