POISONOUS PLANTS 287 



the soil. Animals become accustomed to it, so that 

 amounts of seed which at first cause sickness, later 

 have no injurious effect. The susceptibility of animals 

 to the poison varies both with the species and the 

 individual. Young animals are more readily affected 

 than older ones. It is believed that rodents and sheep 

 are not susceptible, and, as far as is known, grown 

 cattle are only slightly or not at all affected by the 

 poison. Calves, swine, horses, and especially dogs, are 

 more or less susceptible. Concerning birds and fowls, 

 there is some doubt." 



Corn Cockle is included by A. B. Smith l as a simple 

 irritant poison. 



The toxic principle is variously stated to be Sapotoxin, 

 a glucoside, Smilacin, Saponin, or Githagin. Pesch says 2 

 that the seeds contain a poisonous substance called 

 Saponin or Githagin, a bitter property which may cause 

 nervous debility and dysentery. lt The poisonous con- 

 stituent is very freely soluble in water, and possesses a 

 sharp burning taste. It has no odour, but when inhaled 

 in the smallest quantity it produces violent sneezing. 

 When briskly shaken with water it froths like soap. 

 The poison is found in nearly all parts of the plant, but 

 mainly in the kernel of the seed/' 3 The starch grains 

 of Corn Cockle are only about one-fifteenth the size of 

 those of wheat, and are easily distinguishable with the 

 microscope, and by a chemical test with iodine. 



The evidence given above is sufficiently conclusive 

 to show that the ingestion of the seeds of Corn Cockle 

 should always be avoided, and great care should be 

 taken that the seeds are completely removed from 

 cereals before the latter are used for food. 



1 Poisonous Plants of all Countries, 1905. 



2 Die Hittermittel des Handels, 1906. 



3 Farmers' Bull., No. 86, U.S. Dept. Agric. 



