XVII.] climatal variation. 50d 



Thus far, I have spoken only of what may be 

 considered the immediately and intensely practical 

 side of horticultural climatology. It will occur at 

 once to the student that these very observations 

 which I have suggested will afford data for the study 

 of all that fertile subject which concerns the inter- 

 relations of climate and plant life in the evolution of 

 the vegetable kingdom, and it opens the whole field 

 of plant variation and distribution in its relation to 

 environment. Every plant is profoundly modified by 

 the climate in which it is placed ; and if any species, 

 therefore, is cultivated over a wide range of territory, 

 we must expect to find it widely variable between the 

 extremes of distribution. The same variety of apple, 

 for instance, may lose all its distinguishing qualities 

 and marks through a simple transfer to climates not 

 far removed. A study of the statistics of apple 

 exportations during the next ten years will probably 

 show what states or districts produce fruits of suf- 

 ficient firmness and long -keeping qualities to with- 

 stand the journey profitably. And it is not too much 

 to ask of climatology that " it shall tell us why the 

 northern climates develop saccharine elements and 

 high colors, and why the Wisconsin - Minnesota area 

 produces such remarkable waxen and pruinose tints. 

 The influence of climate is nowhere so easily traced, 

 perhaps, as in the business of seed growing. Every 

 seedsman knows that certain climates are not only 

 best adapted to the growth of certain seed crops, but 

 that they exert a profound influence upon the char- 

 acter of the jjroduct grown from them. The study of 

 all these inter-relations of climate and plant -life falls 

 into three subjects : Phenology, or the study of the 



