Third Method (by Lachaume). "By filling in a trench like that described in the first method, by a series of layers of one-third of pigeon or fowl guano, and two-thirds of short manure, containing a large proportion of spent horse droppings, treading it down firmly, watering it if it is too dry, and finishing up with a layer of soil, as described already, we may, at the end of a couple of months, or even a little longer, procure a supply of well-formed cakes of spawn of excellent quality, which may be used in the ordinary manner."
From Mr. Robinson's "Mushroom Culture." "This (French) spawn is obtained by preparing a little bed, as if for mushrooms, in the ordinary way, and spawning it with morsels of virgin spawn, if that is obtainable; and then when the spawn has spread through it, the bed is broken up and used for spawning beds in the caves, or dried and preserved for sale."
From Mr. Wright's book on mushrooms. "French spawn ... is contained in flakes of manure. Neither is it virgin spawn, nor derived immediately from it, ... but is spawn taken from one bed for impregnating another."
Relative Merits of Flake and Brick Spawn.—The flake or French spawn costs about three times as much as the brick or English spawn, and, as it is so much whiter with mycelium than is the brick spawn, many believe that it is more potent and well worth the additional cost. In spawning the beds I use two pounds of flake spawn to plant the same space for which I would use five pounds of brick spawn, and this gives a capital crop, with number of mushrooms a little in favor of the flake spawn, but on account of the larger size of the mushrooms the weight of crop is considerably in favor of the brick spawn. And I find more certainty of a crop in the case of the brick spawn than in the other.
Regarding the respective merits of brick and flake spawn, Mr. Barter, in response to my inquiry, writes me: "I have tried them both, and know brick spawn to be far the best. You see, I do nothing but this mushroom business for a living, so, of course, would use the best kind of spawn for my crop. Generally the French spawn produces one-third less mushrooms than does the brick spawn from the same length of bed, besides, those from the brick spawn are by far the heaviest and fleshiest."
I would here observe that Mr. Barter's remarks apply more to ridge beds out of doors than beds in the cellar or mushroom house. And it is odd, but true, that the flake spawn does not produce as good results in outdoor beds as it does in those under cover.
CHAPTER XI.
SPAWNING THE BEDS.
After the mushroom bed is made up it should, within a few days, warm to a temperature of 110° to 120°. Carefully observe this, and never spawn a bed when the heat is rising, or when it is warmer than 100°, but always when it is on the decline and under 90°. In this there is perfect safety. Have a ground thermometer and keep it plunged in the bed; by pulling it out and looking at it one can know exactly the temperature of the bed. Have a few straight, smooth stakes, like short walking canes, and stick the end of these into the bed, twelve to twenty feet apart; by pulling them out and feeling them with the hand one can tell pretty closely what the temperature of the bed is.