IS ACCLIMATIZATION AN IMPOSSIBILITY? 71 



which will allow it to support a greater degree of cold." This 

 proposition means that plants cannot be bred so that they will 

 be more resistant to cold by ordinary selection, as it would take 

 too long. For hundreds of years on this continent, for ex- 

 ample, we attempted to originate hardy grapes, apples, rasp- 

 berries, plums and sweet cherries from the species originally 

 brought over from the mild climate of southern and western 

 Europe, but no success was obtained. Thousands of orchards, 

 vineyards, and small fruit plantations, wrecked by our test win- 

 ters in the prairie . northwest, show that man's efforts at ac- 

 climatization were in vain. He could not secure a hardy plant 

 from a tender one. In other words, we were starting on a 

 ten-thousand-year job. Nature demands a century of centu- 

 ries for the completion of some experiments. She can do such 

 work, we cannot. 



When it comes to the acclimatization of annual plants the 

 problem is in the main of a different nature. A large late south- 

 ern variety of Indian corn when moved too far north will of 

 course be cut off by early frosts. If moved not too far north 

 there is sure to be some extra early strain within the variety 

 which the observing farmer will select for his next year's seed, 

 and in a few years he will have an extra early variety adapted 

 to his locality. By always selecting for earliness the Indians 

 were able to carry corn, a semi-tropical plant, from South Amer- 

 ica north to Manitoba. This selection was accomplished by the 

 Indians before Columbus discovered America. The Indians 

 cured their seed corn by hanging it up in the smoke of their 

 teepees to dry: and the best modern methods of curing seed 

 corn by artificial heat are in a sense no improvement on this 

 aboriginal method. In parts of south central America corn at- 

 tains a height of twenty feet with kernels several times larger 

 than our northern seed kernels, and it requires seven months 

 to mature. At the northern limit in Manitoba it is perhaps five 

 feet in height 'and requires three months to ripen, but in all this 

 time we 'have simply shortened the season. Corn has not 

 changed its nature in its requirement of extreme heat for ripening 

 seed. As yet we have" no corn that will endure frost to any 

 extent, nor has northern Europe been able to originate a variety 



