It must not be thought that all crops of lupine are poisonous, as lupines are extensively grown on the Continent for fodder purposes and are usually harmless. Even where Lupinosis occurs, considerable quantities of the lupine must be ingested to cause poisoning. The toxicity appears to vary according to soil and certain indefinite conditions, and sometimes even a kilogramme (2·2 lb.) of the plant would suffice to kill a sheep. Poisonous symptoms may sometimes be observed after a single meal. Desiccation does not render the plant innocuous, the seeds and hay being poisonous. In the United States species of _Lupinus_ have caused great loss. In 1898 no fewer than 1,150 of a flock of 2,500 sheep died from eating one species; one sheep farmer lost 700 sheep from the same cause; and 1,900 out of 3,000 sheep died from Lupine poisoning in Montana in 1900. Lupine hay is found to be less harmful to horses and cattle, and Chesnut and Wilcox suggest that this is possibly because as a rule they avoid the pods, while sheep eat them. Lupines in America are very rapid in their action on sheep, which may often die in one-half to three-quarters of an hour after eating a quantity of the pods. Further, there is evidence that sheep may gradually become immune to the poison by eating Lupines regularly, since sheep fed regularly on hay nearly half lupine were unaffected, but others eating the same hay for the first time died in considerable numbers. The lupines are certainly far the most dangerous when they bear ripe seeds—cut and made into hay before the pods form they are much less dangerous. In regard to _L. luteus_ Lander says: “According to the German authorities a daily ration of 1 pound of the whole plant, ⅗ pound of empty pods, or 1⅕ pound of seeds, will produce poisoning.” Various means have been tried to render Lupines harmless, and success is stated to follow heating with steam under a pressure of 2 to 2½ atmospheres.