MIGRATIONS OF PLANTS 
ready to dispute every inch of ground with an 
aggressor. It is very hard for new plants to 
gain entrance into a well-grown forest. 
Man has been of tremendous aid in the dis- 
tribution of plants over the earth’s surface. 
Either consciously or unconsciously he takes his 
plants with him wherever he goes. 
It was the Emperor Chang-Chien who car- 
ried the Bean, Cucumber, Lucern, Saffron, 
Walnut, Pea, Spinach and Watermelon from 
Asia to China about 200 B. C. The period of 
Roman conquest was a great epoch in the his- 
tory of plant migrations. The Peach and the 
Apricot first became prominent as fruits at that 
time. Roman generals introduced the Pear, 
Peach, Cherry, Mulberry, Walnut and many 
ornamental shrubs into England. 
From an obscure native of Bengal, the Sugar 
Cane has become an important plant of wide 
distribution. Coffee, a wild berry of Arabia, 
is now the chief crop of whole countries in the 
West Indies and South America. The yellow 
Maize of America has become a citizen of the 
world. The weak and humble Wheat is the 
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