GERMINATION OF SEEDS 85 
only such features as have an evident bearing upon its 
germination will be considered here. The seed is invested 
by a hard coat (testa), which in some seeds is extremely 
hard, and is evidently a protective structure during the 
more or less prolonged period of 
rest. Within the testa the young 
plantlet is packed, at this stage 
called the embryo (Fig. 81). The 
process of germination is the 
escape of this plantlet from the 
testa. If the embryo of the bean 
be removed from the testa—better 
Fic. 81a.—Section of violet seed, showing 
embryo, endosperm, and testa. 
Fic. 82.—Seedling of bean: 
A, embryo removed from 
testa; B, young seedling 
. - showing hypocotyl, cotyle- 
done after soaking in water for down pe doleciuler O eides 
some time—and straightened out, seedling showing the first 
internode and leaves of the 
it will be found to consist of three een ORE, 
distinct parts (Fig. 82). The 
most conspicuous of these is the two “halves” of the bean, 
which are the seed-leaves (cotyledons) gorged with reserve 
food. These cotyledons stand upon a minute stem, which 
in the seed is curved up against them, and which is called 
the hypocotyl, a name applied to the peculiar stem of an 
embryo. Between the cotyledons, and arising from the top 
