20 
exemplifying the principle which I have laid down, that 
any one branch of science is better understood by having 
a knowledge of other branches, occupy your time a little 
with some observations and reflections on the growth of 
plants from their earliest or seed state. We have all, I 
doubt not, in our early days, taken delight in sowing flower- 
seeds; and have marked, with feelings of transport, the 
first appearance of their green shoots protruding above 
the mould. What our young eyes beheld with exultation, 
| cannot be uninteresting for our matured minds now more 
fully to understand. 
On examining a fresh bean, or one that has been soften- 
ed for some time in water, we observe, first, that its exter- 
nal part isa coat, skin, or husk, enveloping the rest of the 
seed. This coat is really double, but the outer layer or 
cuticle is extremely thin, and not easy to detect. We next 
perceive, on removing this husk, that the seed is not single, 
but formed of two parts, halves, or lobes, placed in juxta- 
position, and only united at one small space near the larger 
end or base, where the scar, or eye, or hilum, as it is tech- 
‘ nically called, is placed. 
The two lobes, or halves of the bean are called cotyledons, 
but large as they are, they do not constitute the most essen- 
tial part of theseed. The small portion, where the two 
lobes are joined is that part, and is, in fact, the entire 
plant, with all its leaves and flowers complete, but com- 
pressed into the smallest bounds; and hence, if we re- | 
moved this little portion, and then planted the rest, we 
might look in vain for the young bean to make its appear- 
ance—the seed would die and rot in the ground, but no 
green leaf would ever spring from it. This little part was 
named the corculum (which means little heart,) by Linnzus, 
and is with equal, or, indeed, greater propriety, 
