The following paper was read by N. E. Hansen : 



Is Acclimatization an Impossibility? 



BY PROFESSOR N. E. HANSEN, 



South Dakota State College of Agriculture and Mechanic Arts, 

 Broo kings, South Dakota. 



The title of this paper would seem to indicate views de- 

 cidedly iconoclastic and heterodox for a Conference on Plant 

 Acclimatization. The casual reader might inquire why we 

 should hold a conference on how to accomplish an impossibility. 

 This line of thought has accumulated slowly in the course of 

 extensive horticultural experiments extending over a series of 

 years, and I will expect some objections from people who have 

 never faced the problem of originating fruits capable of en- 

 during 40 F. with the ground bare of snow. I do not be- 

 lieve in giving winter protection to any plant, because that is hor- 

 ticulture on crutches and hence something to be avoided if pos- 

 sible. 



The argument may be divided into the following sections : 



A. Acclimatization of perennial plants; Botanical names are 

 insufficient for horticulturists; DeCandolle's law. What is pos- 

 sible for nature is impossible for man. 



B. Acclimatization of annual plants; Easily done by man, 

 but is really a process of sifting out of unfit elementary spe- 

 cies ; or minor changes, such as shortening the period of 

 growth. 



Horticulturists who have had to deal with plants in the 

 prairie northwest have learned by costly experience that the 

 source of seed of any variety of tree, or any other perennial 

 plant, determines in a large measure its hardiness in a given 

 locality. Hence my contention is that botanical names do not 

 tell the whole story. Box elders from Southern States winter- 

 kill at the North. The people of Manitoba have learned long 

 ago that they should not plant box elder seed native of the South, 



