82 PABTS OF THE PERICAKP. 



from injur}^, but it is furnished with glands, which secrete such 

 juices as are necessary fur the growth and development of the 

 ovules. 



The pistil in its simplest state consists of a carpel, or folded 

 leaf, with ovules at its margin ; in the fruit the pericarp repre- 

 sents the car])ellary leaf, and the seed the ovules. The trans- 

 formation e>f a leaf into a pistil is not more remarkable than the 

 metamorphosis of a pistil into a fruit. As the ovary hecoraes 

 inature it takes the name of jpcricaT])^ and in its growth becomes 

 either woody or pulj^y fruit. Pulpy fruits absorb oxygen gas, and 

 tlfi'ow off carbonic acid : saccharine or sweet juices are elaborated 

 in their cellular integument. In another stage, the pulpy sub- 

 stance passes through a slight fermentation, the organization is 

 disturbed, the juices sour, the pulp decomposes, and putrefaction 

 ensues. Such is the change which takes place in pulpy fruits 

 dfiring their progress toward maturity and subsequent decay. 



ST.'^The ovary 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 ])erica)y and seed continue 

 to enlarge until they ai'rive at perfection. 



The pericarp often includes other parts of the flower besides the ovary, as the 

 fruit of the liazel and oak consists of the ovary, bracts, and calyx united ; the 

 apple and pear, of the ovary and calyx ; that of the pineapple, of the ovaries and 

 floral envelopes of several flowers combined. Every kind of fruit we see, has been 

 once the ovary or base of the pistil. 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. The size of fruit is not usually pi'opor- 

 tioned to that of the vegetable which produced it. The pumpkin and gourd grow 

 upon slemler herbaceous plants, while the largo oak produces but an acorn. The 

 variety in tlie colors of fruits is supposed to be owuig to certain changes of the 

 chroiauU, ■analogous to the phenomena in the change of colors in leaves before their 

 decay. 



a. In some fruits the pericarp consists of the epicarj)^ the skin 

 of the fruit, or membraneous part which surrounds it, and wliich 

 is a kind of epidermis ; the sarcocaiy^ or mesocarp^ a part more 

 or less fleshy, corky, or coriaceous, often scarcely perceptible, 

 and covered by the epicarp ; the endocarp^ an internal mem- 

 brane of the fruit, which lines the cavity, and by its folds forms 

 the partitions and cells. In the peach, for example, the skin is 

 the ejjicarp ; the pulpy cellular substance which absorbs the 

 juices of the fruit, the sarcocarp ', the shell which incloses the 

 kernel, deprived of moisture, and rendered dry and tough, is the 

 endocarp. Tlie endocarp is also called the jyi^tanien. 



Fig. 98 represents a portion of the carpel or legume of the 

 bean, cut transversely to show the structure of the pericarp : 

 ^, e2ncarj)^ or external epidermis, corresponding to the lower 



Use of the Ovary— Its name in a mature state— Pulpy pericarps.— 87. Perfecting of the pericarp and 

 seed— Organs sometimes included in pericarps, &c. — Color of fruits — a. Epicarp — Sarcocarp — Endocarp 



