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Mushroom Spawn. 

 In mushroom growing one of the first requisites is that of securing 

 a fresh, rehable spawn. The material is easily injured by even brief 

 storage under unfavorable conditions. Most of the spawn used in this 

 country is imported, and the English brick spawn is usually used as 

 it stands transportation and storage better than the French flake 

 spawn, which consists merely of the loose composted material, equiva- 

 lent to ordinary bedding material, through which the mycelium of the 

 fungus has grown abundantly. There is nothing in our climate to 

 render the manufacture of mushroom spawn difficult in America, and 

 good brick spawn is now being made. The important thing is to secure 

 the so-called virgin spawn, or a new growth of the mycelium of Agaricus 

 camipestris. As usually done this leaves to chance the quality and other 

 characters of the mushrooms grown from the spawn. If mushrooms 

 are found growing in lawns or pastures, small trenches are dug be- 

 neath the sod and these are filled with rich manure, with the hope that 

 the vigorous-growing mycelium will penetrate this manure in the course 

 of a few weeks. This usually occurs, and the spawn is said to be very 

 good when production of mushrooms from it is prevented, and, if 

 possible, from any mycelium in the vicinity. When the manure is 

 well penetrated by the mycelium it may be removed and dried, and 

 may be used for the inoculation of spawn bricks, or for the inoculation 

 of small beds. These methods leave too much to chance and there is 

 room for much development along pure culture lines. The "tissue- 

 culture" method consists of filling test tubes or large mouth bottles 

 with fresh stable manure or compost, sterilizing with steam, taking 

 vigorous, well-flavored mushrooms, and with sterilized scalpel and 

 forceps removing with great care bits of the tissue of the mushroom 

 and placing them in the manure in the sterilized tubes. Under favor- 

 able conditions the mycelium will start in a few days, and will spread 

 to all the material in the bottle in three or four weeks, when it may be 

 used as pure-culture virgin spawn. 



The Manufacture of Brick Spawn. 

 The bricks should be solid and compact and with no cracks or irreg- 

 ularities in the surface. In order to secure bricks of this kind and the 

 best growth of mycelium, it has been found by experience that a mix- 

 ture of manure from the cattle shed, and from the stable is desirable. 

 This is usually mixed in the proportion of two-thirds of the former to 

 about one-third of the latter, a small quantity of loam being some- 

 times added. In making the bricks, the material should be somewhat 

 less composted than for making mushroom beds, and it needs to be 

 well selected and raked over, since too much straw in the brick will 

 render it brittle and liable to crack. The mixing of the dried materials 

 is an important process and should be carefully done. The bricks are 



