MUSHEOOM SPAWN MAKING. 55 



that the inocidatioiiH are made from pieces of the tissue of a living 

 mushroom. It is at this stage that selection may be made. One 

 should procure from a bed of mushrooms in full bearing a mushroom 

 which represents the most desirable qualities that are to be found. 

 Size, quality, and general prolihcness must all be considered, as well, 

 also, as other characteristics in any special selections. One may de- 

 sire, for instance, to select from a variety which yields throughout 

 a long period — one wdiich is resistant to higher temperatures, etc. 

 Having found the mushroom from which it is desired to propagate, 

 plants as young as possible may be used, and those which show the 

 veil still intact are especially desirable. With a scalpel, or a pair 

 of forceps, which has been sterilized by passing the blade through a 

 gas flame, or even the flame from an alcohol or ordinary lamp, small 

 !)ieces of the internal tissue ma}^ be removed, and these pieces trans- 

 ferred to the tubes, without, of course, coming in contact with any 

 object whatever which has not previously been sterilized. It is a 

 good idea to Avash the nuishroom first, so that no dust w'ill be made. 

 The plant may then be broken o])en longitudinally and bits of the 

 internal tissue readily removed without fear of contamination when 

 one becomes adept in this kind of manipulation. Immediately upon 

 inoculation the cotton i)lug is rei)laced in the tube, and after all the 

 tubes are inoculated they should be j)ut out of the dust, preferably in 

 a situation where the temperature is about that of an ordinary living 

 room. In the course of several days a slight growth may be evident 

 from the tissue if the conditions have been perfectly sterile. In the 

 course of a week or more the gi'owth shoiUd become very evident, and 

 in three weeks the moldlike development of mycelium should s})read 

 to })ractically all parts of the medium in the tube. The method of 

 making pure cultures and the laboratory apparatus usually involved 

 are shown in Plate VI, figure 2. 



AMien the tubes are thoroughly " run "' the contents may be removed 

 ii.nd used in spawning brick. The contents of a single tulx; may 

 spawn several bricks wdien carefully employed. If no transfers are 

 niade of the growing mycelium from one lot of tubes to another, the 

 writer has not found it at all impracticable or unfavorable to utilize 

 this first lot of l)ricks later in si)awning others. No further trans- 

 fers, how^ever, should be made from these bricks to others under any 

 circumstances in spawn making. As elsewhere indicated, such a con- 

 tinuous transference is injurious to the vigor of the spawn and 

 diminishes the (luantity of nuishrooms produced. 



The coTrhTnercidJ process. — The essentials in si)awn making are (1) 

 a uniform, compact manure brick; {'1) vigorous and well-selected 

 virgin spawn to be used in inoculating the bricks, and (3) favorable 

 conditions for the storage of the bricks during the growth of the 

 spawn. 



