50 PHARMACEUTICAL BOTANY 



plasm about them, cells walls are laid down, endosperm resulting. 

 Germination is the beginning of growth in a seed or plant. The con- 

 ditions favorable to germination are warmth, moisture and presence of 

 air. 



The Fruit 



The fruit consists of the matured ovary and contents, and may include 

 other organs of the flower external to the pistil, but connected with it, as 

 in Clematis, where the long, feathery style renders the fruit buoyant, 

 and, like the fruits of the Thistle and Dandelion, in which the modified 

 calyx serves a similar purpose, is easily scattered by the wind. In the 

 Strawberry and Quince the receptacle becomes thick and succulent, 

 and constitutes the edible portion of the fruit. Other modifications 

 are seen in the hooks or spines, by means of which certain fruits 

 compel animals to assist in their dispersion. Ex.: Cocklebur, Bur- 

 dock, Bidens, Etc. 



Distribution of Fruits and Seeds. — Some fruits, as the cocoanut, are 

 transported by water currents, and are adapted to withstand for a 

 long period the action of salt water. Another of the peculiar means 

 provided by nature for the dissemination of seeds and fruits is that 

 shown in the Sandbox Tree, the fruit of which is hygroscopic, and by 

 absorption of water bursts the pericarp with such explosive force as to 

 cause a loud report and to scatter the seeds in every direction. Birds 

 and fruit-eating mammals, including man, also play a part in the work 

 of distribution. 



Fruit Structure 



The Pericarp, or seed vessel, is the ripened wall of the ovary, 

 and in general the structure of the fruit wall resembles that of the ovary, 

 but undergoes numerous modifications 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, leathery, as the rind of the Orange, or assume the forms 

 seen in the Gourd, Peach, Grape, etc. 



