300 



ORGANOGRAPHY. 



^ig. 646. only persistent but continues to grow, 



and it then forms a lengthened appen- 

 dage to it, as in the Traveller's-joy 

 (Clematis) (fig. 646), and in the Pasque- 

 flower (Anemone Pulsatilla) (fig. 684); 

 the style in these two cases being hairy, 

 the fruit is called caudate, or tailed. 



Pericarp. — The fruit when perfectly 

 formed consists of two parts ; namely, 

 the shell or pericarp, and the seeds, 

 which are contained within it. In the 

 majority of cases the pericarp withers, and 

 the fniit does not ripen when the seeds 

 are abortive. There are, however, many 

 exceptions to this ; thus, many Oranges, 

 Grapes, &c., produce no seed?, but the 

 pericarp is nevertheless fully developed; 

 and in the Bananas, Plantains, and Bread- 

 fruit, the fruits develop most extensively, 

 and become best adapted for food, when 

 the seeds are chiefly abortive. Generally 

 speaking, however, the development of the 

 seeds and pericarp proceed together after 

 the process of fertilization has been ef- 

 fected, and then only perfect fruit can be 

 formed, for although in common language 

 we apply the term fruit in those instances 

 where no seeds are produced, yet strictly 

 speaking such arc not fully formed fruits, 

 but only enlarged and swollen pericarps. 



The pericarp, like the ovary of which it is essentially com- 

 posed, possesses a placenta, to which the seeds are attached ; and 

 the same terms are used in describing the diflcrent kinds of pla- 

 centation, as with those of the ovary; these kinds are usually 

 more evident in the fruit. 



Having now briefly alluded to the seeds as a component part 

 of the perfect fruit, we must leave their particular examination 

 till we have become acquainted with the structure of the ovules, 

 and now proceed, therefore, to the description of the shell of the 

 fruit or pericarp. 



In the majority of fruits, the pericarp consists simply of the 

 walls of the ovary in a modified state; but when the calyx is 

 adherent, it necessarily presents a more complicated structure. 

 Tlie pericarp exhibits three layers or regions (fig. 679), an 

 external, called the cpicarp or exocarp, ep ; a middle, the 

 mesocurp, me; and an inner, tlic endocarp, en. The middle 

 layer, being frequently of a fleshy or succulent nature, is also 

 termed the sarcocarp ; while the inner layer, from its hardness 



Fig. 646. Fruit of the 

 Traveller's-joy {Cle- 

 matis). This fruit is 

 called an Achenium, 

 and is caudate or 

 tailed. 



