[shutt] HAEDINESS IN APPLE TWIGS 153 



of the twig and its power to resist the action of frost, and that those 

 trees whose new growth contains the largest percentage of water as 

 winter approaches, are in all probability the most tender. 



Further, it seems likely that, if hardiness is dependent upon the 

 degree of ripeness of the new growth (indicated by moisture-content), 

 then it is quite possible that it is a quality that can be materially 

 affected by judicious cultural methods. Hardiness, as we have re- 

 marked, is evidently something more than an inherited tendency. 

 It seems probable that it is a quality largely under the influence of 

 the soil condition as regards moisture and temperature in the late 

 summer and autumn months, and probably these factors, rather than 

 the severity of the succeeding winter, determine the tree's immunity 

 from frost. If in northern latitudes vegetative growth be early 

 arrested, and ripening of the new wood thus induced, either by arti- 

 ficial means (pruning and cover crops), or by a dry and cold autumn, 

 varieties now considered tender might prove hardy. 



The determinations of the moisture-content will be made at the 

 regular intervals until the end of May, and then discontinued until 

 the autumn, when the work will be again taken up. The data obtained 

 on this season's growth at the opening of winter, will be of a very 

 important character; for, if the deductions we have made in the pre- 

 ceding statement are correct, the differences at that time in moisture- 

 content between the hardy and the tender varieties should be the 

 largest — ^the former containing the least water; the latter, the most 

 water. 



Sec. IV., 1903. 9. 



