MUSHKOOM SPAWXT. 
81 
who 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 rotted 
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, and 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 roll a 9x6x2 
inch brick, but it shrinks in dr) 7 ing. 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 ordinary English brick spawn. One of our 
prominent seed firms who advertise it write me : “Gen¬ 
uine mill-track spawn used to be the best in England, 
but it has been superseded, although European garden¬ 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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