202 ADAPTATION OF VARIETIES. 



duces plants to flourish for a time ; but, if left to 

 nature, they soon become extinct, or produce an 

 offspring suited to their present surroundings. 



This law of adaptation is one which relates not 

 only to the orders, genera, and species of the vege- 

 table kingdom, but also to its varieties ; and, as we 

 descend the scale, this distinction becomes more 

 nice. For instance, some varieties of the pear lux- 

 uriate upon a rich alluvial soil, while others become 

 diseased and worthless. 



But, as it would be impossible to form an iso- 

 thermal map of any country in which the influence 

 upon the temperature of every little elevation of 

 the surface should be noted, so is it to form one 

 exhibiting the proper varieties of fruit to be grown 

 in every conceivable position. There is no universal 

 law within our knowledge for the government of 

 the cultivator in this respect, and all the data from 

 which we have to judge are the results of expe- 

 rience. 



We avail ourselves of the excellent catalogue of 

 the American Pomological Society, to which we 

 have been enabled to add one or two Southern States 

 from documents in our possession. ; 



As the United States possess such a diversity of 

 climate, many of the most valuable fruits of one 

 section will not arrive at maturity in another. This 

 fact enhances the value of such a table as wc insert, 

 prepared by the able chairman of the General Fruit 



