228 EXPERIMENT STATION. [Jan. 



Illation. It is hoped that these may, in time, be corrected, as 

 we are able to learn more concerning the behavior of these varie- 

 ties under different conditions. 



In Table 6 these same varieties are grouped under their op- 

 timum temperatures for convenience in reference. 



In Table 5 there is also given for some varieties the range of 

 temperature which they can stand without serious deterioration. 

 This is, as already stated, closely connected with the season of 

 the variety, being wide with early sorts and relatively narrow 

 with most winter sorts. Just how much difference there is be- 

 tween the ranges of varieties of the same season is difficult to 

 say. It is complicated with a variety of related questions. 



In the case of a few of the varieties given in Table 5 an at- 

 tempt Is made to give their hardiness with respect to the winter 

 cold. Inasmuch as the ability of the tree to withstand cold de- 

 pends on a variety of factors other than the temperature, it is of 

 no use to attempt to state this in degrees. The designation 

 Ex. H. is used for the varieties equal in hardiness to those classi- 

 fied as 9f the first degree of hardiness ; the designation V. 11. for 

 those of the second degree of hardiness (by the Minnesota Hor- 

 ticultural Society) ; and the designation H., M. and T. for vari- 

 ous degrees of hardiness below these two classes. Many of the 

 more southern sorts are not gi*own far enough north on account 

 of a lack of summer heat to test their winter hardiness in a satis- 

 factory manner. Therefore it is impossible to make any state- 

 ments regarding them, nor would there be any practical value in 

 such statements were they possible. 



