STUDIES OF AMERICAN FUNGI. 



spawn only once in two years, the second year's product would 

 then be further removed from the natural spawn than the first year's 

 product. Where we know that it is removed but one or a few gen- 

 erations from the natural spawn, it is a more desirable kind. For 

 the nearer it is to the natural spawn, other things being equal, the 

 more vigorous the mycelium, and the finer will be the mushrooms 

 produced. 



The brick spawn is sometimes manufactured in this country by 

 growers for their own use, but at present it is manufactured on such 

 a large scale in England that little or no saving is effected by an 

 attempt to manufacture one's own brick spawn in this country. 



Flake Spawn. The flake spawn, or " flakes," is commonly known 

 as the French spawn, because it is so extensively manufactured in 



FIGURE 234. French spawn, or " flakes," ready to plant. 



France. It is made by breaking down beds through which the my- 

 celium has run, and before the crop of mushrooms appears. That 

 is, the bed is spawned in the ordinary way. When the mycelium 

 has thoroughly permeated the bed, it is taken down and broken into 

 irregular pieces, six to eight inches in diameter. Thus, the French 

 spawn, where the beds are made entirely of horse manure, with no 

 admixture of soil, consist merely of the fermented and cured manure, 

 through which the mycelium has run, the material, of course, being 

 thoroughly dried. This spawn may be removed one or several gen- 

 erations from the natural spawn. 



The French growers depend on natural spawn much more than 

 American growers do. The natural spawn is collected from old 



