eee F 
XxXVU1 INTRODUCTORY LESSONS. 
There are many other names applied to 
fruits, which it is not necessary to define 
here. 
The Growth of Ovules. You can 
not study the development of ovules from the 
beginning, without the help of a compound 
microscope, but you ean easily observe all 
stages of growth, from a tiny green speck 
to the full-grown embryo. Most seeds are 
nearly full grown in appearance before the 
embryo is more than fairly visible to the 
naked eye. The seed coat, filled with a 
syrupy or milky, usually sweet, liquid, ap- 
pears to constitute the very young seed. 
With a sharp knife cut in halves a great 
many green peas, in size from half grown 
upward. You ‘will surely find in some of 
them tiny green embryos, and you may get specimens from the size of a 
pin’s head up to those which tightly fill the seed coat. In Fig. 75, at the 
top, is seen—magnified two diameters—the young seed of a lupine, cut so 
as to show the young embryo lying in one end. In the same figure is 
represented a radish pod, laid open so as to show three of the seeds, two 
of which exhibit their partly grown embryos.* Below, at b, is one of 
these magnified, and at a an older one, also magnified. The grown em- 
bryo completely fills the seed. Observe the positions of the embryos in 
relation to the stems of the seeds and the stems of the pods. The lower 
seed in the radish is fastened to the lower side of the pod, the middle 
seed grows to the upper side. The cotyledons increase much more in 
size than the radicle. The embryo evidently grows, in part at least, by 
absorbing the liquid around it. Suppose the embryo of the lupine to quit 
growing at the size represented in the figure, and that the liquid around 
it thickens until it becomes solid. Would not the seed thus formed be 
albuminous ? 
, * These are cut in two. The embryo may be seen through the seed-coat, as represented at b, by hold. 
ing it up to the light. Half of the seed-coat is removed from a. 
