33 



maturity of the latter. The under surface of the cap is provided with 

 leaf-hke or grill-Uke projections, reaching for the most part from the 

 stem to the periphery of the cap. These are termed gills, or "lamellae." 

 They are constantly pink in color in the white or cream-colored species 

 up to the time of (and sometimes even a day after) the separation of 

 the ring from the cap. Subsequently these gills turn brown and even 

 a deep brownish black. In the brown variety the gills are at first 

 grayish brown, but they also become almost black with age. 



There are several distinct varieties of the cultivated mushrooms, 

 which may be distinguished as a white, a brown and a cream-gray 

 variety, known, respectively, by the trade names Alaska, Bohemia and 

 Columbia. 



Spores and Spawn. 



The gills of the mushroom are covered with what appears to be a 

 brownish-black powder, consisting of innumerable minute simple cells 

 in the form of ovate bodies, termed "spores," which serve for the repro- 

 duction of the mushroom. Their function is that of reproducing the 

 mushroom, but they should not be termed seeds. Their structure is 

 so simple and they are in their development so distinct from seeds 

 that spore is the proper designation for the reproductive bodies of all 

 mushrooms, toadstools and the like. 



As a rule, growers do not use these spores directly in growing the 

 cultivated mushroom. Under favorable conditions, however, each 

 minute spore is capable of germination and of producing a thread-like 

 growth, which by subsequent branching and with extensive ramifica- 

 tions may produce in the course of weeks a spider-web-like, or thi'ead- 

 like growth, penetrating the soil, compost or other substratum upon 

 which the spore happens to have germinated. When this thread-like 

 growth which develops from the spore is of sufficient extent to be 

 readily observed, it is known as "spawn." The spawn represents what 

 may be termed the vegetative stage of the fungus. It may grow to a 

 considerable extent, and during this growth it stores up nutriment. 

 Under favorable conditions there are then formed, on threads growing 

 near the surface, small pin-head or cushion-like areas of growth. These 

 pin heads represent the earliest visible stages of what we know as 

 mushrooms. With further grov>rth and modifications they become the 

 buttons which we find growing superficially upon the mushroom bed 

 or bursting through the soil. From the pin-head stage to the fully 

 expanded mushroom there may be a period of growth ordinarilj^ requir- 

 ing at least a week. 



The mushroom differs much from our ordinary plants, there being 

 no such organs as root, stem and leaf, and a well-differentiated body 

 is only formed when the mycelial threads have stored up nourish- 

 ment and are ready to develop the mushroom, or sporophore, which 

 is to bear the reproductive bodies or spores. The spores have seldom 

 been used in a commercial way. The spawn maker has depended upon 



