19 
This mixture is of about the consistency of dough. The jar is 
then placed, together with many dozens of others prepared in 
the same way, in a large tin steamer or sterilizer, (Fig. 11, 
Plate I), to be steamed for four or five hours. It is then taken 
out and the cap removed in order to break the now solid mass 
of steamed meal into fragments about the size of a walnut. 
This is to allow the fungus-growth to penetrate more easily 
and to grow throughout the entire mass. It is now thoroughly 
steamed during four or five days for six or eight hours daily. 
This thorough steaming is for the purpose of kiiling off the 
myriads of vegetable organisms present, in other words to per- 
fectly clean or sterilize the ground in which the fungus is to be 
grown. The cotton plug allows free access of air, but stops 
all bacteria and spores of fungi from falling in, or otherwise 
contaminating the meal. This is very important, for if any 
other organisms are present they are sure to spring up ata later 
period and crowd out the disease-producing form. 
The spores are now introduced into the sterilized jar as fol- 
lows: Aplatinum needle, made by inserting a piece of platinum 
wire in a glass rod, is placed in a gas jet and heated white hot 
to destroy all germs that may be clinging to it, after which it 
is touched to a pure culture, either in a tube or another jar, and 
from thence into the prepared jar through the tube in the cap, 
the cotton plug having been removed for this purpose. The 
plug is replaced and the jar laid on its side ina shady but fairly 
warm place. In the course of a few days a small white spot of 
fluffy threads will be seen where the needle touched the meal. 
Soon this growth of fluffy mould spreads over the entire sur- 
face, penetrating into the interstices between the pieces of meal, 
and uniting the whole in one mass of fungus-growth, which 
soon takes on a floury or powdery surface of creamy-white, 
caused by the production of conidia or spores. If now the jar 
be opened a pleasant odor resembling that of mushroons is 
noticeable. 
After the culture has been allowed to dry for a short time it 
is removed from the jars and cut into small pieces, to be placed 
into small round tin boxes. In the course of a day or so the 
growth spreads over the freshly cut surfaces, making a smooth 
even growth of creamy-white. Itis now ready to be sent to 
the place where it is to be used for infection. 
