76 MASSACHUSETTS HORTICULTURAL SOCIETY. 



vation of Indian corn, near London, but without success. The 

 Rhododendron arboreum was introduced into England from Nepal 

 more than fifty years ago, and has been confined to greenhouse 

 culture ever since, repeated sowings having had no effect in ac- 

 climating it. But after a time it was hybridized with the hardy 

 American species introduced some 3'ears before, so that the pro- 

 gen}'' were half arboreum and half Cataivbiense, and these seedlings 

 were crossed again with the hardy species, making them one-fouvth 

 arboreum and three-fourths Cataivbiense. By this process the deep, 

 rich, superb colored flowers of the Indian species were finally com- 

 bined with the hardy constitution of our American shrub ; but the 

 hybrids were tender exactly in proportion to the amount of Indian 

 blood they retained. Canary birds have been bred here for many 

 generations without the slightest effect in acclimation. Our sum- 

 mers, as well as those of Canada are as much tropical as those of 

 New Orleans, enabling us to produce many tropical plants at that 

 season in perfection ; but this is not acclimation. Gladiolus bulbs 

 ma}' survive the winter when left deep in the ground, and covered 

 so thickly with snow that the frost does not reach them ; but they 

 do not become acclimated, or at least they have not so far. Mr. 

 Hovey agreed with Dr. Waters that frost has, to a great extent, 

 the same effect on plants as heat. Seeds which require much heat 

 to germinate will endure a temperature of — 20°. He had had 

 amaryllis seeds so exposed which came up better than those that 

 had not been subjected to frost. Acclimation has been pretty 

 thoroughly examined and discussed by scientific men, who have 

 considered it a failure. 



Mr. Wilder said that the reason why seeds plucked early germi- 

 nate more freel}', is that the pericarp is not so hard. He had been 

 trying for forty-five years to believe in acclimation, and after 

 spending much time and money i^ importing plants and endeavor- 

 ing to adapt them to our climate, he had come to the full conclu- 

 sion that the acclimation of plants in places not naturally suited 

 to them is a chimera of the imagination. The human constitution 

 will frequently endure the change of country and climate, but the 

 extent to which plants can bear these changes is fixed by immu- 

 table laws, and all attempts to acclimate such as are not naturally 

 congenial, will fail in the end, except within very narrow limits. 

 Not, however, that a tree or plant may not sometimes endure 

 greater degrees of cold or heat than it is subject to in its native 



