LARKSPUR POISOlSriNG OF LIVE STOCK. 85 



during one season at Greycliff, Mont., on Delphinnmi cucullatwn 

 and D. hicolor. 



4. These experiments 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 such a way that they will not have an opportunity to 

 feed upon the larkspur may prevent losses. In the case of Del- 

 fhinium meriziesii 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. J), 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 



