THE GERMS OF FERN LIFE 
9 
other. The one is the radicle or the germ of the future root, 
the other is the plumule or the germ of the future stem, which 
in the process of development gives rise to branches and 
leaves, or to smaller stems and leaves. Wherever or however 
a seed may fall, there can be no change in the respective 
functions of its radicle and plumule. The one is sure to strike 
downwards into the soil, and the other is equally sure to rise 
above the ground. 
The spore is not so constituted, nor does it become 
developed after the manner of the seed. It consists, in fact, 
of a tiny cell, which is of various shapes in the different 
genera of Ferns, sometimes being globular, sometimes oval, 
and occasionally angular in form, with an exterior that is 
sometimes plain, sometimes streaked, or otherwise beautifully 
marked, and either smooth or bristling with little points. 
From the part of this minute germ-cell which happens to lie 
downwards proceeds the root, whilst from its upper portion 
proceeds the frond. When the spore has fallen into a congenial 
position for germination, the process of development com- 
mences by the enlargement and multiplication of the cell of 
which it consists. This cell becomes divided after a short 
time, and forms an aggregation of little cells, which take the 
shape when expanded of a minute patch, like a tiny leaf 
laid flat on the ground. This leafy scale, as it may he 
termed, is mostly irregular in shape, but is usually somewhat 
round or heart-shaped. Its colour is green, and it bears the 
somewhat euphonic name of prothallus. Under the prothallus 
— which attaches itself to the earth or rock by fine rootlets — 
begin to be produced a number of other little cells of a pecu- 
liar kind. They are in fact of two kinds, and may be called 
for the sake of distinction, sperm cells and embryo cell's. 
One of the latter contains a frond-bud or imperfect germ, 
imperfect because it has to be fertilized before it can commence 
the process of development. The sperm cells contain 
