56 PASTURE AND RANGE. 
aluminium sulphate, similar to that used for Zygadenus 
poisoning, forms a chemical antidote, neutralizing the 
poison not already absorbed. 
BUTTERCUP FAMILY—Ranunculaceae. 
LARKSPURS—Delphiniwm spp. 
The poisonous effects of European Larkspurs have 
been known for centuries. One species, D. Staphisagria 
Reanples, and L., called Stavesacre, was used as a poison / 
Conditions of | f0r lice. Many species are common in the 
Poisoning west of Canada and the United States, and 
have occasioned great losses among cattle 
on the ranges. Marsh and Clawson place them next to 
the “loco” weeds in the number of animals killed, and 
Glover, in 1906, estimated the annual monetary loss, in 
Colorado alone, at $40,000. All parts of the plants a 
poisonous, the seeds most of all. Leaves and roots are 
most harmful in early spring. The effects gradually de- 
crease until after flowering, when practically all of the 
alkaloids seem to collect in the seed and the rest of the 
plant becomes harmless. 
Stockmen have blamed the Larkspur for a large part 
of their losses in both cattle and sheep, and until a few 
years ago this opinion was entertained even by those who 
should have scientifically investigated the matter. In 
1916, however, Marsh and Clawson published an account 
of experimental work which led them to believe that sheep 
can withstand the poison, probably on account of its 
prompt excretion by their kidneys. In repeated instances 
sheep were fed large quantities of the plants and in no 
case was any injury produced. They found horses to be 
susceptible to the poison, though they do not voluntarily 
