392 FORCING GARDEN. 



like leaven, be indefinitely multiplied- and preserved. 

 If not to be otherwise procured, it may be produced, 

 or apparently generated, by placing quantities 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 re- 

 ferred to above ; and, as it has some conveniences, par- 

 ticularly for those who have not extensive means, it 

 may be proper to- give some account of it. Horse-drop- 

 pings should be laid out from the stable into a very dry 

 place, as free from straw or litter as possible. There 

 they should be firmly trampled down with a man's 

 feet, to prevent fermentation."" -The droppings from the 

 horse-track of a thrashing-machine form an excellent 

 material in the spring ^;ime ;. for there the droppings 

 are kept dry, aiid are thoroughly trodden by the horses' 

 feet. Beds may then be formed two or three feet broad, 

 and of any length. A layer of the droppings about 

 eight or ten inches thick is first deposited, and covered 

 with loamy earth to the depth of two or three inches ; 

 then another layer of droppings of the same thickness, 

 covered like the former ; and, lastly, a third layer, 

 with its covering. The whole should grow narrower as 

 it advances in height. When the bed is finished it is 

 covered with straw, to protect it fr9m rain and from 



