Fungi. 221 



potatoes, dahlias and many other tuber and bulb bearing 

 plants. 



Other points of interest might be noticed in connection 

 with these strange plants, such as the tendency of some to 

 grow in circles, their unusual places of growth, their gro- 

 tesque shapes, their dual forms and their alternate genera- 

 tions, but we must hasten to a brief notice of their relations 

 to other plants and to animals. 



Fungi are essentially parasitic plants. Even in many 

 instances in which the Fungus appears to grow from the 

 ground like other plants, a careful examination reveals the 

 fact that the mycelium is attached to the roots of grasses or of 

 other plants, to buried sticks or bits of wood, or is creeping 

 amidst vegetable mold or the excrement of some herbi- 

 vorous animal. These plants revel upon and hasten the de- 

 composition of dead or dying plants. Old trunks of trees, 

 rotten wood and dead twigs are favorite abodes of many 

 species, the mycelium creeping among the woody tissues, 

 loosening, softening and sometimes discoloring them. The 

 numerous instances of " dry rot " in timber are often to be 

 attributed to fungoid origin. Merulius lacrymans, in this 

 way, has proved a great pest to buildings and shipping in 

 England. Living plants, too, and these sometimes both 

 vigorous and useful, become the victims of these destruc- 

 tive little agents which have not inaptly been styled 

 " princes of the powers of putrescence." It has been a 

 mooted question whether parasitic Lichens are injurious to 

 the plants they inhabit, or not; but in the case of plant- 

 attacking Fungi there is but one side to the question so far 

 as the plant attacked is concerned. Cultivated plants are 

 sometimes attacked by them more unrelentingly and more 

 fatally than uncultivated ones. This fact is exemplified in 

 the case of Sjrfioeria morbosa, a Fungus commonly known as 

 Black knot. Dr. Schweinitz, more than thirty years ago, 

 wrote concerning it as follows : " This species occurs on 



