86 
PART3 OF THE PERICARP. 
themselves, until the character of the fruit is fully exhibited. So in 
the heart of youth, the germs of virtue or vice may, for a while, be 
apparently dormant and inactive, but growing more vigorous and 
powerful, they at length unfold themselves, and reveal either a cha- 
racter matured into what is lovely and desirable, or marked with 
qualities of a disagreeable and deleterious nature. 
LECTURE XV. 
THE FRUIT — PERICARP PARTS OF THE PERICARP — LINN^US^S CLASSIFICATION 
OF FRUITS MIRBEL's CLASSIFICATION OF FRUITS. 
The Fruit. 
The fruit is composed of two principal parts, the pericarp and 
seed. The term pericarp is derived from per-?' around, and ^arpo^ 
seed or fruit ; it signifies surrounding the seed. All that in any fruit ^ 
which is not the seed belongs to the pericarp. 
Let us now inquire into the progress of the frait from its first ap- 
pearance in the germ to its mature state. When you analyze a 
flower, you often find it necessary to ascertain the number of cells 
contained in the germ. In making this examination, what appear- 
ance does the interior of the germ present, when exposed by cutting 
it horizontally? You see there minute bodies of a pale green col- 
our, and an apparently homogeneous nature: each of these is called 
an ovule* and their outer covering, an ovary. These ovules, before 
the fertihzation of the germ by the pollen, are scarcely perceptible ; 
after this period, and the fading of the corolla, the ovules increase 
in size, and the embryo and other parts which constitute the seed 
become manifest. The ovary enlarges with the growth of the ovules ^ 
the use of this covering is not confined to the mere protection of the - 
seeds from injury, but it is furnished with glands, which secrete such 
juices as are necessary for the growth and development of the 
ovules. As the ovary becomes more mature, it takes the name of 
vericarp. Pericarps in their growth become either woody or pulpy ; 
the latter absorb oxygen gas and throw off carbonic acid ; saccha- 
rine juices are elaborated in their cellular integument. In another 
stage, the pulpy substance passes through a slight fermentation, the 
organization is disturbed, the juices sour, the pulp decomposes, and 
putrefaction ensues. Such is the change which you may see in 
pulpy fruits during their progress towards maturity and subsequent 
decay. 
Parts of the Pericarp. 
The germ being fertilized, the parts of the flowe!" which are not 
necessary for the growth of the fruit, usually fade, and either fall 
off or wither away. The pericarp and seed continue to enlarge 
until they arrive at perfection. Every kind of fruitf you can behold 
has been once but the germ of a flower. The size of fruit is not 
usually proportioned to that of the vegetable which produced it. 
The pumpkin and gourd grow upon slender herbaceous plants^ 
while the large oak produces but an acorn. 
* From o?5wm, an egg. 
t The term fruit, in common language, is limited to pulpy fruits which are proper 
for food ; but in a botanical sense, the fruit includes the seeds and pericarps of all ve- 
getables. 
Fruit, the two principal parts— Derivation and signification of the word pericarp- 
Ovules — Ovary — Use of the ovary — Its name in a mature state — Pulpy pericai-ps — 
Germ— Size of the fruit not in proportion to the plant that produces it. 
