258 STUDIES OF AMERICAN FUNGI. 



It would be interesting, and it might also prove to be profitable 

 to growers, if some attempt were made to grow natural spawn under 

 conditions which would perhaps more certainly produce a supply. 

 This might be attempted in several different ways. Stall-fed horses 

 might be fed a ripe mushroom every day or two. Or from the cap 

 of ripe mushrooms the spores might be caught, then mixed with oats 

 and fed to the horse. Again, the manure piles might be inoculated 

 by spores caught from a number of mushrooms. Manure might also 

 be collected during the summer months from the highways and aside 

 from the probable natural inoculation which this material would 

 probably have from the spores blown from the meadow and pasture 

 mushrooms, additional inoculation might be made. The manure 

 obtained in this way could be piled under sheds, packed down thor- 

 oughly, and not allowed to heat above ioo F. These piles could 

 then be left for several months, care being used that the material 

 should have the proper moisture content, not too dry nor too wet. 

 This is given only as a suggestion and it is hoped that some practi- 

 cal grower will test it upon a small scale. In all cases the tempera- 

 ture should be kept low during the fermentation of these piles, else 

 the spawn will be killed. 



One of the methods of obtaining natural spawn recommended by 

 Cuthill (''Treatise on the Cultivation of the Mushroom") is to 

 collect horse droppings all along the highways during the summer, 

 mixing it with some road sand and piling it in a dry shed. Here it 

 is packed down firmly to prevent the heat rising too high. A ** trial " 

 stick is kept in the pile. When this is pulled out, if it is so hot as 

 to ** burn the hand," the heat is too great and would kill the spawn. 

 In several months an abundance of the spawn is generated here. 



Mill'-track spawn. ** Mill-track " spawn originated from the spawn 

 found in covered roadways at mills or along tram-car tracks where 

 horses were used. The accumulation of manure trodden down in 

 these places and sometimes mixed with sawdust or earth, provided 

 a congenial place for the growth of the mycelium. The spawn was 

 iikely introduced here through spores taken in with the food of the 

 horse, or brought there from highways, if they were not already in 

 the soil from mushrooms grown there. It would be then multiplied 

 by the growth of the spawn, and from spores of mushrooms which 

 might appear and ripen. The well tramped material in which the 

 mycelium grew here, when broken up, formed convenient blocks of 

 spawn for storage and transportation, and probably led to the 

 manufacture of brick spawn. 



Manufactured spawn The manufactured spawn, on the other 



