POISONOUS FUNGI AND OTHER SPORE -BEARING PLANTS 39 



extremely dangerous and usually fatal. There are only eight species 

 belonging to this terrible class, viz.; Amanita phalloides, A. solitaria, 

 A. virosa, A. vena, A. citrina, A. mappa and Amanitopsis volvata. 

 Two poisons are found in fungi of this class: phallin and amanitatoxin 

 which have been discussed as to their activity on a previous page. 



Horse-tail (Equisetum arvense). This fern plant has underground 

 rhizomes divided into nodes and in- 

 ternodes. Short secondary roots arise 

 from the subterranean nodes which are 

 surrounded by brown, whorled scale 

 leaves. The first shoot to appear early 

 in the spring is chlorophylless with in- 

 ternodes and nodes. A whorl of brown 

 scale leaves arise from the nodes. The 

 summit of this shoot terminates in a 

 sporangiferous cone consisting of sporo- 

 phylls bearing bag-like sporangia filled 

 with green spores covered by four hygro- 

 scopic elaters. Later a green, branching 

 shoot arising from the rhizome and 

 persists through the season (Fig. 14). 



Cases. The investigations of Rich and 

 Jones show that the horse-tail causes 

 much and frequently fatal poisoning of 

 horses in Vermont. During the summers 



of IQOI and 1902 Rich in his professional the left come up in spring, the much- 



work about Burlington had twenty-three %?^^g*fc 



Cases of horses poisoned by this plant the hay; in the center are the under- 



and his records showed forty-one cases $f * LaZj?SZ 



which he had attended within five years. Clovers, Bulletin 94. Vermont Agric- 

 In Europe a number of cases of equisetosis ^f E *t erimenl s ' ation ' Ma ^ 

 have been reported. 



Symptoms. The first evidence of trouble is more or less an emaciated 

 conditions. The animal in two to five weeks loses control of its muscles, 

 sways and staggers about. Later it has paralysis of the hind legs and as 

 a result it falls down. Attempting to rise the horse becoming nervous 

 struggles violently to arise. Finally there is general paralysis, uncon- 

 sciousness and coma. The lungs and kidneys become congested, the pulse 



