THE SEED AND ITS GERMINATION. 5 
~ make a sketch of it and label the shell or covering of the seed and the 
kernel within this. 
Taking another soaked seed, chip away the white outer shell, called 
the testa, and observe the thin, greenish inner skin, the tegmen, with 
which the kernel of the seed 
is closely covered. 
‘Strip this off and sketch the 
uncovered kernel. Note that 
at one end it tapers to a point. 
This pointed portion, known 
as the caulicle, will develop 
after the seed sprouts into the 
stem of the plantlet, like that 
shown at fc in Fig. 1. 
Split the halves of the kernel 
entirely apart from each other, 
noticing that they are only 
attached for a very little way 
next to the caulicle, and ob- 
serve the thickness of the 
halves and the slight uneven- 
ness of the inner surfaces. 
These halves are called seed- 
leaves or cotyledons. 
Have ready some_ seeds 
which have been soaked for 
24 hours and then left in a kee eon 
s one. — . i inati 
loosely covered jar on damp e Castor Bean and its Germination. 
: I, longitudinal section of the ri ; - 
blotting-paper at a tempera- |. = : enable: a = 
ce. ; minating seed; he, caulicle; c, cotyledon ; 
ture of 70° or over until they e, nourishment stored around the cotyledons ; 
have begun to sprout. s, testa; x, thickened knot at end of seed; 
Split one of these seeds WwW, primary root ; w’, secondary roots. 
apart, separating the cotyle- 
dons, and observe, at the junction of these, two very slender pointed 
objects, the rudimentary leaves of the plumule or first bud. 
+3. Examination of the Bean. — Study the seed, both dry and after 
12 hours’ soaking, in the same general way in which the squash-seed 
has just been examined.! 
-,1The larger the variety of bean chosen, the easier it will be to see and sketch the 
several parts. The large red kidney bean or the horticultural bean will do well for 
this examination. 
