3 82 



THE NON-VASCULAR PLANTS 



mycelium is of no value to him unless it produces an 

 abundant crop of the reproductive organs. Mushrooms 

 are usually grown in cellars or in mushroom houses, which 

 are but dimly lighted. Light is not needed for the crop. 

 To get the right temperature, the right moisture, and 

 the right food supply is the problem. The spawn 



is spread in manure 

 which needs to be at 

 just a certain stage of 

 decay in order to pro- 

 duce the best results. 

 The manure is covered 

 with a thin layer of 

 black earth. Pres- 

 ently, if conditions are 

 right, young mush- 

 rooms, called buttons, 

 begin to break through 



FIG. 179. A portion of the surface of one of the 

 gills of a common mushroom showing the way 

 in which the spores are borne. Note the club- 

 shaped structures bearing two prongs at whose 

 tips the spores are borne. These club-shaped 

 structures are basidia. See context. 



the soil. 



All true fungi fol- 

 low this general plan 

 of growth and nutri- 

 tion that we have noted as to toadstools and mushrooms, 

 but their reproductive habits are quite dissimilar. Some 

 fungi have sex methods of reproduction in addition to the 

 non-sex methods. As to nutrition, all true fungi have 

 hyphae which absorb food. They also assimilate it. The 

 whole work of nutrition goes steadily on in the mycelium, 

 and then, when the conditions are just right, sporophores 

 appear, the spores are scattered, and the sporophores dis- 

 appear again. They shrivel up and die. The mycelium 

 continues its work as long as it can. When the conditions 



