THE CULTIVATION OF MUSHROOMS 



1385 



it brittle and liable to crack. The mix- 

 ing of the dried materials is an impor- 

 tant process and should be carefully 

 done. The bricks are molded in a frame 

 of the size desired, the material being 

 pounded into the frame by means of a 

 mallet. If one follows the most common 

 method, the bricks are only slightly 

 dried, and then spawned. A piece of 

 virgin spawn is inserted at either end, 

 immediately after which they are rap- 

 idly dried before being stacked for the 

 growth of the spawn. By another pro- 

 cess the bricks are Immediately dried 

 without the insertion of the spawn ma- 

 terial, which is later placed in depres- 

 sions made between two adjacent bricks 

 as they are being stacked for the growth 

 of the spawn. In stacking, the bricks 

 are arranged in layers of one or two 

 bricks in thickness, depending upon the 

 method of spawning. Upon each layer 

 there is placed a very thin stratum of 

 fresh manure containing a little clean 

 straw. After the layer of manure is 

 added a very slight watering with a 

 rose spray is given. The whole is then 

 covered with clean straw or litter and 

 left for several weeks, when, under fa- 

 vorable conditions, it should be found 

 upon investigation that the spawn has 

 "run" throughout the bricks. 



Occasional examinations of the bricks 

 should be made, however, where ex- 

 perience is lacking, in order to see that 

 they are not too moist and that the 

 growth may not go too far. When prop- 

 erly made, the bricks should be well 

 penetrated by a mold-like growth of my- 

 celium. A considerable cording or 

 threading of the mycelium indicates un- 

 favorable conditions, or that the growth 

 has progressed too far. The latter usually 

 means that the spawn may not prove 

 as vigorous as desirable. 



By the methods above outlined, using 

 pure cultures as virgin spawn, a small 

 amount of spawn for experimental pur- 

 poses has been made by the Department 

 of Agriculture during the past two 

 years. Under favorable conditions this 

 spawn has given unusual yields. Pure 

 cultures were also furnished two grow- 



ers who wished to co-operate in the 

 experiment. As a result of this co-op- 

 eration there was put upon the market 

 in 1903 by practical growers an excel- 

 lent grade of American brick spawn of 

 "pure-culture" origin. There Is every 

 reason to believe that this means a great 

 advance. 



There can be no question that spawn 

 made by the method above outlined will 

 be a known product; then, if the mush- 

 room from which cultures were made 

 was properly chosen, there may be con- 

 stant improvement and selection; and 

 furthermore, it is believed that the grow- 

 er will know what to expect or to de- 

 mand. Pure-culture methods undoubt- 

 edly involve some extra expense; but, 

 if in time it may be possible to dispense 

 with the bacteriological precautions, or 

 to make the spawn by direct inoculation 

 of spores into the bricks, then the same 

 result will be accomplished without pure- 

 culture methods and without the addi- 

 tional expense. 



It is to be hoped that spawn makers 

 will also adopt for the spawn the trade 

 names suggested, or at least some trade 

 names for the spawn made from the 

 various strains or varieties or from the 

 cultivated mushroom. When purchasing 

 his spawn, the grower should be able to 

 know whether he is obtaining the white 

 (Alaska), the brown (Bohemia), the in- 

 termediate cream gray (Columbia), or 

 other similar strains. 



It appears to the writer unfortunate 

 that mushroom spawn, at least in brick 

 form, should sell by the pound. Seeds- 

 men and growers alike are interested 

 in reducing weights when the character 

 of the product is not at all affected. It 

 would be better, having well in mind 

 the cubical content of the brick, to sell 

 the spawn by the brick. Of two bricks 

 differing by half a pound in weight, it 

 may very well be that the lighter is bet- 

 ter, owing to the absence of pebbles and 

 of any excess of loam. 



Storage of Spawn 



It is possible to ruin good spawn by 

 improper storage, even in a relatively 

 short period of time. Spawn should be 



