104 
PERICARP AND SEED. 
illation what appearance has the interior of the germ presented 
when exposed, by cutting it horizontally? You have there 
seen minute bodies of a pale green colour, and an apparently ho- 
mogeneous nature ; these are called ovales and their outer cov- 
ering is termed an ovary. These ovales before the fertilization 
of the germ by the pollen, are scarcely perceptible ; after this pe- 
riod, and the fading of the corolla, the ovales increase in size, 
and the embryo and other parts which constitute the seed become 
manifest. The ovary enlarges with the growth of the ovales ; 
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 develop- 
ment of the ovales. As the ovary becomes more mature it takes 
the name of pericarp. Pericarps in their growth, become either 
woody or pulpy ; the latter absorb oxygen gas and throw off 
carbonic acid ; saccharine juices are elaborated in their cellular 
integument. In another stage, the pulpy substance passes 
through a slight fermentation, the organization is affected, the 
juices sour, the pulp decomposes and putrefaction ensues. Such 
is the change which you may see in the orange, apple, cucum- 
ber, &c. during their progress in decay. 
Pericarp and Seed. 
The germ being fertilized, the parts of the flower which are 
not necessary for the growth of the fruit, usually fade, and 
either fall off, or wither away. The germ continues to enlarge 
until it arrives at perfection. Every kind of fruit* you can see 
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 the gourd grow upon slender herbaceous 
plants, while the large oak produces but an acorn. 
Every pericarp is formed of a parenchymous substance ; this 
substance is surrounded externally by a cuticle called the epi- 
carp , internally by a membrane called the endocarp, and an in- 
termediate part called the mesocarp. In a peach, for example, 
the kernel is the seed, the fleshy substance the pericarp ; the 
skin is the epicarp ; the pulpy cellular substance which absorbs 
a great quantity of sap and constitutes the principal part of the 
fruit, is the mesocarp ; the shell deprived of moisture and nour- 
* 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 vegetables. 
Progress of the fruit considered — Ovales — Ovary — Use of the ovary — Its 
name in a mature state — Pulpy pericarps — Germ — Size of fruit not in pro- 
portion to the plant that produces it — F.picarp — Endocarp — Mesocarp — 
