The Greenhouse and Frame 245 
only ^ in. The spores must be sown thinly, in soil made 
of 2 parts peat, i part leaf mould, i part loam, and 
j part sand. Before sowing, the soil must be sterilized 
— that is, heated to 21 2° F., the boiling-point of water. 
This is done to kill any algae that may be in it, as these 
would multiply rapidly and prevent the development of 
the prothalli. The spores should be sown in a pan, 
well drained and filled with the above compost, and 
should not be covered with soil, as the prothalli are pro- 
duced only on the surface. They should then be placed 
in a close, moist atmosphere, and shaded. A box covered 
with glass, or under a bell glass, &c., is suitable for this 
purpose. Care must be taken not to allow any condensed 
moisture to drop on to the soil, either before or after the 
prothalli are formed, as this would cause them to “damp 
off”. A moist atmosphere is required, as fertilization is 
only effected under water, but the slightest quantity is 
sufficient for this purpose. 
When the young Fern plants are large enough to 
handle, they should be pricked out into other pans filled 
with a similar compost to the above, and placed about 
1 in. apart each way. They must again be placed in a 
moist, warm atmosphere, and shaded. As growth pro- 
ceeds the young plants may be potted into 60s pots, using 
the same compost again. At this stage the Fern plants 
are most useful for room decoration. 
As growth continues they may be moved into 4-in. 
pots, and again into 6-in. ones, which should be large 
enough unless specimen plants are required. For the 
latter potting a compost of 2 parts of peat, 1 part of leaf 
mould, 2 parts of loam, and ^ part of sand should be 
