254 VETBEINAEY TOXICOLOGY 



activity to gratiolin, a drastic purgative. Poisoning, which 

 might possibly result from it, takes the form of super- 

 purgation. 



Linaria. — Linaria vulgaris, or toad-flax, L. spuria, or 

 round-leaved linaria, L. cymhalaria, or ivy linaria, and 

 L. elatina, or pointed linaria, are all acrid and poisonous, 

 and have a repulsive smell and nauseous taste. Animals 

 do not readily eat the plants, and poisoning, therefore, is 

 very rare. Toad-flax is common in hedges and field borders, 

 the others less frequent, and they ought to be included as 

 noxious weeds. 



Pedieularis, Rhinanthus, and Melampyrum. 



Pedicularis. — This genus includes Pedieularis palustris, 

 or red rattle, distributed over marshes, wet meadows and 

 ditches, and P. sylvatica, or louse-wort, more widely distri- 

 buted over moist pastures, meadows, and heaths. Many 

 species are found in the United States, chiefly the Western. 



Rhinanthus. — Rhinanthus Crista-galli, the rattle, or 

 common rhinanthus, is a meadow and pasture weed, which 

 often causes injury to the herbage, and whose grains are 

 liable to become mixed with cereals. 



Melampyrum. — Melampyntm arvense, or purple cow- 

 wheat, occurs in cornfields of South-Eastern England and 

 Norfolk, and is injurious to crops. The grains, like those 

 of rhinanthus, may become mixed with cereals. 



These plants contain a glucoside, rhinanihin, or closely 

 allied compounds, in their seeds, and thus may be dele- 

 terious components of forage or flour. The doses for 

 animals would be very large, for Cornevin quotes experi- 

 ments in which 35 grammes of the grain and over 2 pounds 

 of the fresh plant did not affect rabbits. 



The general effect of rhinanthin is that of a saponin, and 

 reference may be made to that substance for an account of 

 its action and chemical recognition in flour or meal. 



