1913] The Ottawa Naturalist. 49 



Island, do not grow in quantity where they are likel; e eaten 



by cattle. All the species of Aconite are more or less poisonous, 

 but no injury to cattle has been recorded. R. sceleratus is the 

 most dangerous species of the genus Ranunculus, growing as it 

 does in marshes and along ditches where cattle are likely to eat 

 it with other forage plants; it is also the most poisonous species. 

 The juice of several species will, if rubbed on the skin, produce 

 blisters and sometimes ulcers. 



Although the berries of Mountain Ash. Pyrus Aucuparia, 

 are poisonous to man, P run its is the onlv rosaceous genus that 

 causes serious injury either to man or stock. The leaves of all 

 the species may be eaten while fresh, but when wilted contain a 

 virulent poison, hydrocyanic or prussic acid. P. serotina is the 

 most poisonous species in the north, although P. pennsylvanica 

 and P. virginiana are almost equally so. Poisoning is frequently 

 caused by cattle and sheep eating the wilted leaves, and children 

 occasionally die from eating the kernels of the seed. So many 

 sheep are killed by browsing Pr units leaves when being driven 

 along trails in the west that in many places the bushes have 

 en cut out, in others the dangerous places are marked by flags. 

 Leaves wilted in bright sunlight to about 75 per cent, of their 

 original weight, or until they appear slightly limp, yield the 

 maximum amount of prussic acid. 



Many of the Leguminosae are injurious to stock and it is 

 to this family that all the "loco weeds" belong. Of these, in 

 Canada at least, Oxytropis causes the greatest damage to sheep, 

 horses and cattle. No Canadian species of Astragalus is known 

 to cause injury. One effect of eating any of the "loco weeds" 

 is that a depraved appetite is developed and the animals prefer 

 the "loco weed" to wholesome food, and will even dig up the 

 roots to satisfy their craving. The first stage of the disease is 

 the effect on the nervous system, which in time drives the animal 

 frantic; in the second stage there is emaciation, exhaustion and 

 finally death from starvation. Thermopsis rhombifolia, which is 

 common in the prairie country, is said to be injurious to stock, 

 and several cases of children having been poisoned by eating the 

 seeds are recorded by the Canadian Department of Agriculture. 

 It is only in recent years that it has been shown that poisoning 

 from lupine occurs almost always when the plant is fruiting, 

 and experiments in Germanv have shown that the active poison, 

 ictrogen. is found chiefly in the seeds and pods. 1 ; er the 



first frosts destroy other vegetation that the lupine is eaten in 

 the greatest quantity. Of one band of 200 sheep let into a field 

 of lupine for a short timewhen in a hungry condition. 100 had died 

 within a few hours and 50 others succumbed later on, and on 

 another occasion 150 rams were given a feed of lupine hay and 



