222 COMPOUND ORGANS OF PLANTS. 



of birds. It is in this way that Phytolacca decandra, or the 

 common pokeweed, appears to have been dispersed over the 

 whole of North America. The berries of this plant are eaten 

 by the robin, the thrush, the wild pigeon, and many other 

 birds, which thus carry them hundreds of miles from the plant 

 which produced them. In this manner we can account for a 

 fact which every practical botanist and observer of nature must 

 have noticed, viz. : the sudden appearance of a single plant in 

 a place where its species was entirely unknown before. 



Some pericarps are conveyed by the rivers into which they 

 fall, or by the waves of the ocean, many hundreds or thousands 

 of miles from the countries which originally produce them. In 

 this manner many of the native plants of France, Spain, and 

 other adjacent countries, have been naturalized in England ; 

 and the pericarps of tropical climates are conveyed to the coasts 

 of Norway and Scotland. The foreign pericarps which are 

 annually left on the Norway coast, are principally cashew- 

 nuts, bottle-gourds, cocoa-nuts, and the fruit of the dogwood 

 tree. These are often in so recent a state, that they would 

 unquestionably vegetate were the climate favorable to their 

 growth and existence. When carried to countries better suited 

 to their nature, they germinate and colonize with a new race of 

 vegetables the land on which the ocean has cast them. In this 

 manner it is that the coral islands, as soon as they appear above 

 the waves of the Pacific, are speedily covered with a crop of 

 luxuriant vegetation. The cocoa-nut is well adapted for this 

 purpose,, as it grows luxuriantly in salt water, and it is proba- 

 bly the first arborescent species which vegetates on these newly- 

 formed lands. 



Most of the seeds thus carried abroad never germinate at 

 all, as they either fall into situations unfavorable to their 



