218 GBEENHOUSE MANAGEMENT. 



portions of old mushroom beds, containing the spawn in 

 the form of white threads, are placed in a dry place, they 

 will preserve their vitality for several years, but should 

 not be relied upon for spawning mushroom beds. 



As generally used, however, mushroom spawn is in 

 the form of bricks, or flakes, the former being known as 

 English and the latter as French spawn. It is all im- 

 ported, and the amount used is steadily increasing, the 

 annual consumption being several hundred thousand 

 pounds. The bricks (Fig. 79) are about eight inches 

 long, five inches wide and one and one-fourth inches 



FIG. 79. BRICK SPAWN. 



thick. They are made by mixing two parts of fresh 

 horse manure, one part cow manure and one part loam, 

 and adding a little chopped straw. This is made of 

 about the consistency of mortar, and after being worked 

 over two or three times, at intervals of two days, it can 

 be made into bricks with molds, or by cutting it with a 

 spade ; when first made, the usual size of a brick is nine 

 by six by two inches. They should be set on edge and 

 placed in the sun and air for a few days, and when about 

 half dry a small piece of spawn should be placed in the 

 center of each brick, carefully filling up the holes with 



