388 THALLOPHYTES 



like sporophores on the sides of trees and stumps. In the family 

 to which the Hydnums belong the hymenium is borne on tooth- 

 like projections (Fig. 341)- In another family the sporophore 

 is much branched and the hymenium covers the surface of the 

 branches (Fig. 342}. As to the texture of the sporophore, that 

 varies widely in the different families. In some families it is 

 gelatinous and without definite shape. It is fleshy in the Toad- 

 stools and Mushrooms and in some of the Bracket Fungi it be- 

 comes as hard and persistent as wood. 



FIG. 343. Some of the roots and the lower portion of the trunk of an 

 Apple tree which has been killed by the Toadstools. 



Destructive Toadstools and Bracket Fungi. Some Toad- 

 stools attack the roots of trees and cause the disease called Root 

 Rot. This disease occurs on a number of fruit trees, such as the 

 Apple, Plum, Cherry, and Peach, and on many shrubs and forest 

 trees. In Figure 843 is shown some Toadstools which have 

 destroyed an Apple tree. The Toadstools usually cause the death 

 of the roots, and this results in killing the tree. The mycelia of 

 the Toadstools probably enter the roots through wounds. 



