CHAPTER XIII 
THE FRUIT 
The Fruir consists of the matured pistil (carpel or carpels) 
and contents, or ovarian portion thereof, but may include other 
organs of the flower which frequently are adnate to and ripen 
with it. Thus, in the Apples, Pears, and Quinces, the receptacle 
becomes thick and succulent, surrounds the carpels during the 
ripening process and forms the edible portion of these fruits. 
In Dandelion, Arnica, and many other members of the Com- 
posite, the modified calyx or pappus adheres to the ovary during 
its maturation into the fruit and renders the fruit buoyant. In 
Wintergreen, the calyx becomes fleshy, surrounds the ovary, 
reddens, and forms the edible part of the fruit. In Ground 
Cherry (Physalis), the calyx enlarges considerably and encloses 
the ovary in an inflated colored bladder. Involucres frequently 
persist around and mature with the fruits. These may be 
membranous as in Anthemis, Matricaria and other Composite, 
leathery and prickly as in the Chestnuts, scaly woody cups 
(cupules) as in the Oaks, or foliaceous cups as in the Filberts. 
Occasionally, as in the Fig, Osage Orange, Mulberry, etc., the 
fruit may consist of the ripened flower cluster or inflorescence. 
Fruir STRUCTURE 
Tue Pericarp.—The Pericarp, or seed vessel, is the ripened 
wall of the ovary. In general the structure of the fruit wall 
resembles that of the ovary, but undergoes numerous modifica- 
tions in the course of development. 
The number of cells of the ovary may increase or decrease, 
the external surface may change from soft and hairy in the flower 
to hard, and become covered with sharp, stiff prickles, as in the 
Datura Stramonium or Jamestown weed. ‘Transformations in 
consistence may take place, and the texture of the wall of the 
ovary may become hard and bony as in the Filbert, leathery, as 
297 
