Trees and Timber 



357 



food supply and are found upon fewer hosts. They chiefly 

 fall into two groups; one bearing its spores upon gills 

 (Fig. 194); the other with its spores borne in pores. 

 Still others bear their spores upon spines. In describing 

 the fructification of the causal fungi for recognition pur- 

 poses it is necessaiy to 

 note especially the 

 stalk or stipe, and the 

 cap or pileiis (Fig. 194). 

 A cap with no stalk is 

 "sessile." To deter- 

 mine the particular 

 species of fungus that 

 is present, it is usually 

 necessary to examine 

 the sporophore, and 

 even then expert or 

 special knowledge is 

 needed.* The deter- 

 mination of the species 

 of the fungus is, how- 

 ever, not necessaiy to 

 proper treatment, since 

 this is much the same 

 for all. 



Care should be ex- 

 ercised in felling trees 

 to avoid injuring other 

 trees. In forests in 



Fig. ISO. — \\'ound of proijurly removed 

 limb, beginning to heal over. After 

 Ind. Agi'. Exp. Sta. 



general, cull material and infected standing trees should be 

 burned to prevent spore formation. Excision of the infected 

 tissue should be practiced in case of especially valuable trees. 

 When there are pruning-wounds, apply an antiseptic to the 

 exposed wound to prevent the effective germination of spores 

 upon its surface. Suitable antiseptics are tar or paint. 



* Useful books in such classification are given in the bibliography, 

 Nos. 381-387. 



