THE MUSHROOM. 373 
litter instead of the hot water, or in which rhubarb stalks 
may be forced. The windows are furnished with shutters 
to regulate the admission of light, much of which is not 
wanted; and they are movable, to permit the ingress of 
air. 
Mushrooms are propagated from what gardeners call 
spawn, and botanists micelium, being a collection of mat- 
ter resembling white mouldiness, crossed with vegetable 
threads. It may be obtained from old pastures, the floors 
of disused stables, decayed mushroom beds, or purchased 
from nurserymen in the form of dicks charged with spawn. 
When once obtained, it may, like leaven, be indefinitely 
multiplied and preserved. If not to be otherwise procured, 
it may be produced, or apparently generated, by placing 
quaatities of horse-dung and rich loam in alternate layers, 
and covering the whole with straw, to exclude the rain and 
air. Mushroom spawn commonly appears in the heap in 
about two months after the dung and earth have been laid 
together. The almost impalpable seeds seem to adhere to 
the grass, hay, or oats, on which the horse feeds, and to 
resist the action of the animal’s stomach. The droppings 
of stall-fed horses, or of such as have been kept on dry 
food, are found preferable for this purpose. 
The old method of growing mushrooms has been refer- 
red to above; and, as it has some conveniences, particular- 
ly for those who have not extensive means, it may be pro- 
per to give some account of it. Horse-droppings should 
be laid out from the stable into a very dry place, as free 
from straw and litter as possible. There they should be 
firmly trampled down with a man’s féet, to prevent fermen- 
tation.. The droppings from the horse-track of a thrashing 
machine form an excellent material in the spring time; 
for there the droppings are kept dry, and are thoroughly 
