THALLOPHYTES 



55 



as its name implies, is an edible form ; while its near relative, 

 Boletus Satanas, as its name implies, is a deadly form. 



The mycelium of a mushroom extends widely in the decay- 

 ing material in 

 which it grows 

 (Fig. 39). In 

 some cases it ex- 

 tends under the 

 bark of trees and 

 does them great 

 damage. Every 

 one must have 

 seen these 

 thready growths 

 in forest soil or 

 in rotting logs 

 and stumps. 

 This mycelium 

 sends up sporo- 

 phores, which are 

 the structures 

 commonly called 

 mushrooms (Fig. 

 40). They differ 

 from the ordi- 

 nary sporophores 

 of Fungi in con- 

 sisting of many 



branches Orgr.n- 



i-7orl tnn-o+Vior in 

 T/0 & ei 



a Complex Struct- 



ure. They may 

 be called " compound " sporophores, to distinguish them 

 from the simple sporophores of the other groups. These 

 sporophores produce a vast number of spores (Fig. 41), 



FIG. 41. Sections through gills of a mushroom : A, gills 

 hanging from the cap (pileus) ; B, single gill enlarged, 

 showing the basidium layer ; C, much enlarged view 

 ^ a Portion f a basidium layer, showing the basidia 

 bearing spores. After SACHS. 



