250 



simple interlacing mycelium. There are none of the highly 

 developed forms of tissuesi seen in higher plants, the struct- 

 ure of fungi being always simple. 



Not all fungi are injurious, many are harmless, some are 

 beneficial and even a necessity to our existence. Of the 

 larger fleshy forms a considerable number are valuable food 

 plants as nutritious as fish, oysters or beef, and there is no 

 reason why they should not form as common an article of 

 food among us as they do in *^^he countries of Europe. The 

 fact that we import large quantities of mushrooms from 

 Europe which could be easily produced in this country and 

 of a much better quality than the imported article is sug- 

 gestive of one of the undeveloped resources of industry and 

 cultivation that is lying dormant in our midst. It is, how- 

 ever, the parasitic forms of fungi, that at present concern 

 us most. 



Classes of Parasitic Fungi. 



Parasitic fungi may be conveniently classified in three 



groups : 



(1) Internal free parasites floating or swimming in the cell 

 sap of plants and absorbing their vitality. Such a parasite 

 is the one that produces pear blight and such are the para- 

 sites that assist in producing the various rots of different 

 garden vegetables. 



(2) External fixed parasites, forming a cobwebby growth 

 of mycelium on the surface of leaves or fruits and drawing 

 nourishment from the plant by means of suckers. Such 

 are the powdery mildew of the grape and those of a similar 

 nature found on many other plants. 



(3) Internal fixed parasites, growing entirely within their 

 host-plant, sapping its nourishment, and only appearing at 

 the surface when ready to reproduce by means of spores. 

 This group includes by far the greater number of species 

 of parasitic fungi that infest cultivated plants and include 

 the rusts, smuts, downy mildew of the grape, black rot, the 

 ripe rot of apples and other fruits, etc., etc. 



