86 PARTS OF THE PERICARr. 



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 vvith 

 qualities of a disagreeable and deleterious nature. 



LECTURE XV. 



THE FRUIT — PERICARP — PARTS OF THE PERICARP — LINN.EUs'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 jje/'^' around, and A- orpos 

 seed or fruit ; it signities 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 fruit 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 oin«7e,* and their outer covering, an ovary. These ovules, before 

 the fertilization 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 flower 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. 



* Prom ovum, an egg. 



t The term fruit, in common langiingp, is limited to piilpv fruits which are proper 

 fe, ibod; 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 pericarps- 

 Germ — Size of the fruit not in proportion to the plant that produces it. 



