MUSHBOOM SPAWiT. 81 



tvho are the cause of this ; the market men find there is 

 money in growing mushrooms and they are going into it. 



Spawn comes in the form of dry, hard, solid manure 

 bricks, and also in the form of flakes of half robted 

 strawy manure. These bricks and flakes are completely 

 permeated with the mushroom mycelium. 



The brick spawn is commonly known as English 

 spawn, and what is imported into this country is made 

 in England, mostly about London. The bricks made by 

 the different manufacturers vary a little in size and 

 weight ; in some cases ten bricks go to the bushel, in 

 others fourteen, and in others sixteen. This last is the 

 commonest sized brick, aud weighs exactly a pound, and 

 measures about eight and one-half inches long, five and 

 one-fourth inches wide, and one and one-fourth inches 

 thick ; it is what the London spawn makers call a 9x6x2 

 inch brick, but it shrinks in drying. In retailing brick 

 spawn in this country it is sold by weight and not by 

 measure. 



Mill-track mushroom spawn is advertised by some of 

 our seedsmen, but what they sell under this name is 

 only the ordinai-y English brick spawn. One of our 

 prominent seed firms who advertise it write me : " Gen- 

 nine mill-track spawn used to be the best in England, 

 but it lias been superseded, although European garden' 

 ers still call for English spawn under the name of ' mill- 

 track.' " The real mill-track spawn is the natural spawn 

 that has spread through the thoroughly amalgamated 

 horse droppings in mill-tracks or the cleanings from 

 mill-tracks. It is usually sold in large, irregular, some- 

 what soft lumps, and is much esteemed by spawn makers 

 for impregnating their bricks, but nowadays, that horses 

 have given place to steam as a motive power in mills, we 

 have no further supply of mill-track spawn for use in 

 spawning our mushroom beds. We do not feel this loss, 

 however, as the spawn now manufactured by our best 

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