100 



SCIENTIFIC AGRICULTURE. 



Fig. 7. 



THE FRUIT. 



The ultimate object of the whole vegetable organization 

 appears to be the production of fruit; which is the agent 

 through which the reproduction of the species is accomplished. 

 After the seed is perfected in annual plants, they soon wither 

 and die : the flower always precedes the fruit, and is neces- 

 sary to its development and perfection. The fruit consists of 

 two parts, viz: &e pericarp and the seed, or the seed-covering 

 and the seed: the pericarp is wanting in some plants, but the 

 seed is essential in all. In the coniferous plants, as the pine, 

 spruce, &c., the seed is naked and destitute of the pericarp. 



The PERICARP is the part which envelops 

 the seed, whatever be its substance or struc- 

 ture. Fig. 7. In the peach and plum, this is 

 a fleshy, pulpy substance, in the oak and 

 Fi S' 8 - walnut, a dense hard shell : (fig. 8.) 

 thus the structure and composi- 

 tion of the pericarp varies in dif- 

 ferent plants, from a soft watery 

 pulp to a dense shell. The pro- 

 cess of the ripening of fruit con- 

 sists of certain chemical changes produced 

 by the action of light, heat and air, and 

 perhaps other agents. Pericarps have 

 received specific names, according to their 



Fig. 9. form and structure: that of the pea and bean 

 is called a pod, that of the walnut and but- 

 ternut is called a nut, that of the apple and 

 pear, a pome, that of the currant and whor- 

 tleberry, a berry, &c. Fig. 9. 



This figure represents the pericarp, or seed 

 capsule of the cenothera. 



