270 STUDIES OF AMERICAN FUNGI. 



only by the consumer, but are desirable for shipment. These mush- 

 rooms are much thicker through the center of the cap than those 

 usually grown in houses at a room temperature of 60 F. For this 

 reason, the mushrooms in these caves spread out more, and the 

 edges do not turn up so soon. Since the cap is so thick and firm at 

 the center, it continues to grow and expand for some little time after 

 having opened, without turning up on the edges, and without be- 

 coming black and unsightly underneath. These large and firm 

 mushrooms are not only desirable for their shipping qualities, but 

 also, if they are not too large, they are prized because they are of 

 such a nice size for broiling. 



It is quite likely that one of the important conditions in produc- 

 ing mushrooms of this character is the low temperature of the mine. 

 The temperature here, in July and August, rises not higher than 58 

 F., that is, the room temperature of the mines ; while in the winter 

 it falls not lower than 52. The growth of mushrooms, under these 

 conditions, may not be quite so rapid as in a house maintaining a 

 room temperature of 60. The operator may not be able to grow 

 so many crops from the same area, during the same length of time ; 

 but the very fact that this low temperature condition retards the 

 growth of the mushrooms is perhaps an important item in produc- 

 ing the firm and more marketable product, which can be allowed to 

 grow longer before it is picked. It is possible, also, that another 

 condition has something to do with the firmness and other desirable 

 qualities of these mushrooms. It is, perhaps, to be found in the 

 fact that natural spawn is largely used in planting the beds, so that 

 the spawn is more vigorous than that which is ordinarily used in 

 planting, which is several or many generations distant from the 

 virgin condition. 



The methods of picking in this mine differ, also, from those 

 usually employed by growers of mushrooms. The mushrooms are 

 pulled from the bed in the same way, but the operator carries with 

 him two baskets and a knife. As fast as the mushrooms are pulled, 

 and while they are still in hand, before the dirt can sift upon the 

 other mushrooms, or fall in upon the gills of those which are open, 

 the lower part of the stem is cut off. This stem end is then placed in 

 one basket, while the mushrooms which have been trimmed are 

 placed in another basket. In cutting off the stems, just enough is 

 cut to remove the soil, so that the length of the stem of the mush- 

 room varies. The mushrooms are then taken to the packing room 

 in the cleanest possible condition, with no soil scattering therefrom 

 or falling down among the gills, as occurs to a greater or lesser ex- 



