284 POISONOUS AND MECHANICALLY INJURIOUS PLANTS 



fly agaric. The pileus is shiny white, pale yellow, or olive in 

 color, without distinct scales. When moist it is slightly sticky. 

 The gills and the long, slender stalk are white. The base of the 

 stalk is more bulbous than that of fly agaric, and is bordered by 



Fig. 107. — FLY AGARIC {Amanita muscaria). 



This fungus sometimes causes deaths, both in the human family and among foraging animals. 



An extract of it is used effectively as fly poison. 



a sac-like membrane, often large, but usually only a mem- 

 branous rim (Fig. 108). 



The toxic principle acts directly on the red blood corpuscles, 

 lowering the vitality of the animal. It acts slowly, however, 

 the first symptoms usually appearing from nine to fourteen hours 

 after eating. The symptoms are severe pain in the abdomen, 

 nausea, and diarrhea, followed in two to eight days by coma, 

 and death soon results. There is no known antidote for this 

 poison. 



MECHANICALLY INJURIOUS PLANTS 



A large number of plant genera contain species that cause 

 mechanical injury to stock. Sandburs, cockleburs, and certain 

 cacti need only be mentioned in this connection. Many such 



