200 



BULLETIN 193. 



have been worked out quite satisfactorily. The studies have 

 been made in New York State, chiefly at Ithaca and in the 

 forests of the Adirondack Mountains. 



A word might be said at the outset in regard to the relation of 

 these wood destroying fungi to others, as well as in regard to 

 their structure. They are among the higher fungi and belong 

 to the larger group known as the Hymenomycetes to which the 

 mushroom also belongs. In fact it is becoming customary with 



some to apply the 

 term " mushroom " 

 to all of the Hymen- 

 omycetes. However 

 widely these plants 

 differ in their form 

 and structure they all 

 agree in the general 

 character of their 

 fruiting surface. It 

 forms a thin layer or 

 "membrane," cover- 

 ing definite parts of 

 the fruit body, and 

 consisting of innum- 

 e r a b 1 e club-shaped 

 cells standing side by 

 side. Each one of 

 these club-shaped 

 cells is called a basid- 

 ium, and usually 

 bears four spores. 



There are several 

 large families, or 

 orders in the group. 

 I will call attention to 

 a very* 'few in each 

 family in order to show more definitely the form and general 

 character of the species examined here. In one of these families 

 the fruit body is often spread over the surface of the wood in 



56. Polyporus borealis. Fruit bodies growing 

 from wound on hemlock spruce. 



