1 INTRODUCTION TO BOTANY. 



Of the Fruit, 



One of t!ie organs of reproduction, in order that the student 

 may understand the brief sketch given of the Natural System 

 of Jussieu. 



The J'r2di is composed essentially of two parts, the perica?-]), 

 and the seed. 



The pericai-p, or covering of the seed is always present, 

 however thin : there are in fact, no naked seeds. 



The j?mcarj9 is always composed of three parts: viz. 1. a 

 thin external membrane, called the epicarp : 2nd. of an 

 internal membrane, lining the seed-bearing cavity, called the 

 endocarp. Between these two membranes is a fleshy part, 

 called the sarcocarp or mesocarp. See Plate 12. 



The seeds are attached in the pericarp to a peculiar fleshy 

 body, called the trophosperm or placenta. 



When the surface of the trophosperm has manifest prolon- 

 gations, each of them bearing a seed, these prolongations are 

 called podosperms. 



The arillus being only an expansion of the trophosperm, 

 belongs not to the seed, but to the pericarp. The arillus 

 never occurs in plants, whose corolla is monopetalous. 



Concerning the pericarp in general, we may observe that 

 its axis is sometimes material, and has a real existence : it is 

 then called columella : or the axis may be fictitious or rational, 

 that is to say, represented by an imaginary line passing from 

 the base to the summit of the pericarp, and running through 

 its centre. 



The columella is a small column, which supports the 

 different parts of the fruit. 



The number of the valves of a pericarp is always known by 

 the number of longitudinal sutures visible on its outer surface. 

 The valvar dehiscence (that is, opening of the valves) is three- 

 fold: 1st. it may take place in the middle of the cells, that is 

 to say, between the partitions, which, in that case correspond 

 with the middle part of the valves. This is called loculicidal, 

 as in most ericinece. See Plate 12. 2nd. the dehiscence 

 may occur, opposite to the partitions., it is then called septici- 

 dal, as in the scrophularinece. See Plate 12. 3rd. when the 



