74 
THE NATURALIST AND COLLECTOR 
come diffused in the atmosphere and 
fall upon the ground. Most of the 
spawn is made near London. One man, 
John F. Barter, grows about 21,000 
pounds of mushrooms a year, and in 
summer manufactures about 160,000 
pounds of spawn for sale. This one 
man makes about three times as much 
spawn as the entire importation into 
the country amounts to, which shows 
how much greater the mushooom grow¬ 
ing industry is in Europe than in 
America. 
The spawn is made from fresh ma¬ 
nure, which is formed into bricks and 
spread to dry. When about half dry a 
hole is made in the side of each brick 
and a piece of old spawn about an inch 
square is inserted. At a certain stage 
the bricks are removed and baked in 
order to arrest further vegetation until 
required for use.. 
In and around Paris, where the cham¬ 
pignon is eaten by everybody, enor¬ 
mous caves are used for the industry, 
-but about Philadelphia most of the 
mushrooms are grown in green houses. 
They are cultivated most extensively 
in winter. The beds are prepared about 
the first of October, the spawn is cut 
into small pieces and planted at a dis¬ 
tance of about nine inches apart. In 
forty days from the time of spawning 
the first crop is ready for picking, and 
the spawn does not become exhausted 
until June. 
