XIX.] VARIOUS OPINIONS. 333 



Poland ; Duchess, Romenskoe and many other sorts 

 with green foliage at this time [a time of drought in 

 Iowa when our native apples suffered] , are native to 

 the dry, porous, loose bluffs west of the Volga, where 

 the annual rainfall is only from twelve to fifteen 

 inches. We find this general law to hold good with 

 the apple, pear, cherry, plum, forest trees, shrubs, 

 and even with the grasses and weeds." 



"It is no exaggeration to say that with almost 

 every plant which has long been cultivated, varieties 

 exist which are endowed with constitutions fitted for 

 very different climates." — Darwin. 



" We must transport as large number as pos- 

 sible of adult, healthy individuals to some interme- 

 diate station and increase them as much as possible 

 for some years. Favorable variations of constitution 

 will soon show themselves, and these should be care- 

 fully selected to breed from, the tender and unhealthy 

 individuals being rigidly eliminated. 



"As soon as the stock has been kept a sufficient 

 time to pass through all the ordinary extremes of 

 climate, a number of the hardiest may be removed 

 to the more remote station and the same process gone 

 through, giving protection if necessary while the 

 stock is being increased, but as soon as a large num- 

 ber of healthy individuals are produced, subjecting 

 them to all the vicissitudes of climate." — A. R. 

 Wallace. 



"Domesticated plants can be gradually acclima- 

 tized to bear a degree of heat or cold which in their 

 wild state they would not have supported." — Marsh. 



