FOREST PROTECTION 117 



apothecia in the succeeding spring. 

 The most important representative of 

 this family in Europe is Peziza. 

 III. Order Basidiomycetes. 



Spores carried on basidia of definite shape 

 and she, and bearing a fixed number of spores. 

 1st. Family Uredinece. 



All are injurious parasites, the 

 mycelium being in the intercellular 

 spaces of the tissues (particularly in 

 the leaves) of higher plants. These 

 fungi change their hostplants, showing 

 a double generation, and develop sev- 

 eral kinds of asexual spores, according 

 to the season and to the host; aecidio- 

 spores and pycnoconidia in spring; 

 uredospores in summer; teleutospores 

 in autumn, which in the following 

 spring develop basidiospores. The my- 

 celium from the basidiospores enters 

 the first host and develops the seci- 

 dium stage (formerly the genus Ae- 

 cidium) with secidia and pycnidia. The 

 next stage on a different host develops 

 the uredospores (formerly genus Ure~ 

 do), and in autumn the thick walled 

 teleutospores. 

 2nd. Family Hymenomycetes. 



Basidia imbedded in a common 

 hymenium which clothes, in Agari- 

 cacece, a series of radial lamellae on the 

 under side of the pileus, and in Poly- 

 poracece and Boletacece, the inner sur- 

 face of pores. 



In a few genera no distinctive 

 fructifications are formed (Exobasi- 

 dium vacdnii, parasitic and causing 

 hypertrophy on Ericaceae). 



Another arrangement of the orders 

 and families of fungi might be made 

 with reference to pathogeny: 

 a. The groups 

 Uredinece 



Ustilaginece 



(so-called "Smuts") 

 Peronosporece 

 Exoascece 



(witch broom) 



contain parasites only, 

 so that no proof of 

 parasitism is required. 



