594 



Mushroom Spawn Making. 



[Jan., 



partially filled (about two-thirds) with the manure or half- 

 decayed leaves upon which it is desired to grow the virgin 

 spawn. A plug is inserted in each tube, and the tubes are then 

 sterilised in a steam boiler or under pressure. If sterilised under 

 steam pressure, as in an autoclave, it is necessary to use about 

 fifteen pounds pressure and to allow the tubes to remain at this 

 pressure for from fifteen minutes to half an hour. If the 

 sterilisation must be effected in a boiler or open water bath, it is. 

 desirable to boil the tubes for at least one hour on each of two 

 or three successive days. 



With the tubes thoroughly sterile, the next step is to make 

 the cultures or inoculations. By the tissue-culture method the 

 inoculations are made from pieces of the tissue of a living 

 mushroom, and 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 prolificness must all 

 be considered. Having found the mushroom which it is desired 

 to propagate, plants as young as possible may be used, and 

 those which show the veil still intact are specially desirable. 

 With a scalpel, or a pair of forceps, first sterilised by- 

 passing through a gas flame, small pieces of the internal 

 tissue may be removed, and these pieces transferred to the 

 tubes. It is well to wash the mushroom first, and the plant 

 may then be broken open longitudinally and bits of the internal 

 tissue readily removed without fear of contamination. Imme- 

 diately upon inoculation the cotton plug is replaced in the tube^ 

 and after all the tubes are inoculated they should be put 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 

 growth should become very evident, and in three weeks, the 

 mouldlike development of mycelium should spread to practically 

 all parts of the medium in the tube. 



When the tubes are thoroughly "run" the contents may be 

 removed and used in spawning brick. The contents of a single 

 tube may spawn several bricks when carefully employed. If no 

 transfers of the grow ing mycelium are made from one lot of 



