INTERNATIONAL BOTANICAL CONGRESS. 195 
migrations, and already raises a portion of the veil which covers the 
obscurity of their origin. All this ought to offer a real interest to 
horticulturists. We are beginning to have the power of stating in 
figures the effect of each climate upon vegetation; consequently, the 
possibility of a given species enduring the mean or extreme climatal - 
conditions of that country to which it is desired to introduce it. 
ready we can show, in the clearest manner, the analogy between the 
vegetation and climate of certain regions widely separated the one from 
the other, and point out in which cases new attempts at cultivation 
> should be tried or where they should be discouraged. A celebrated 
geologist was able to say, beforehand, there is gold in such a part of 
New Holland; and gold was found there. We can also say the Olive-tree 
and the Cork Oak will succeed in Australia; the eastern and temperate 
region of the United States is favourable to the growth of Chinese 
plants, more particularly to that of tea; and we can assert that that 
part of America included between San Francisco and the Oregon terri- 
tory will one day supply wines as varied and as excellent as those 
European ones produced between Portugal and the Rhine. It isa 
singular fact that the two principal beverages of the civilized world, 
wine and tea, which produce similar stimulating effects, but which to a 
certain extent are the substitutes one for the other in different countries, 
present also in the mode of cultivating them the most marked resem- 
blances and differences. The Vine and the Tea-plaut succeed best on 
stony, barren hillsides, of which they sometimes increase the value a 
hundredfold. 
According to the exposure, the soil, the cultivation and manner. of 
preparing the produce, wine and tea are obtained of unquestionable 
excellence ; whilst the neighbouring crops, but a short distance off, 
may be more or less ordinary in quality. The two shrubs require a 
temperate climate, but the Vine needs heat and no rain during summer, 
whilst the Tea-plant requires rain and but little summer-heat ; the re- 
sult of which is that these two species are almost geographically 
— epe Vine-growing countries will never produce tea, and 
oes yön will say these examples belong rather to agriculture, and 
concern neither botany nor gardens. I maintain the contrary. It is 
science, in the present day, which points out what plants to cultivate, 
and into what countries to introduce them. Horticulture makes the 
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