186 Mississippi Valley Horticultural Society. 



imbibed or molecular water heretofore described, together with the conse- 

 quent shrinking of the tissues, that pushes off the bark, with or without a 

 radial, longitudinal split. Such a crystalline growth does take place in the 

 tissues of plants, and is readily seen by microscopical examinations of frozen 

 succulent stems. The cause is amply sufficient for the result, and the only 

 point upon which to hesitate is : Does this kind of ice formation really occur 

 in the tissues between the bark and wood of the apple trees ? We may pos- 

 itively say that, under the usual favorable condition of things in our climate, 

 it does not. It can not readily be found this year after a temperature of 

 — 28° Fahr. But, after all, may not the phenomenon occur under certain 

 and peculiar unfavorable circumstances or combinations of circumstances ? 



Having pretty well examined the problem, from what the courts call cir- 

 cumstantial evidence, I submit the following as the chief factors in the com- 

 bination of causes leading to the unwelcome result : If, in mid-summer, a 

 severe drouth occurs, the tree is checked in its growth so far that the stimu- 

 lating influences of a warm, moist, spring-like autumn starts afresh the ac- 

 tivity of the cambium cells, and if growth of new cells does or does not occur 

 — usually it does not — in the cambium of apple trees, though shoots start, 

 the solution of the stored materials and undue absorption of water puts the 

 tissue in condition to freeze in the manner mentioned, when exceptional 

 cold follows in winter. The more severe the drouth the more the likelihood 

 of such an autumn, spring-like start. Florists know verj' well that to cause 

 a plant to grow out of its season, nothing so prepares it as a preceding rest, 

 brought about by withholding water. Without such rest the same stimulat- 

 ing influences will not operate. In its normal season maturation may result 

 instead of new growth, under tl\e attempts to secure the latter. There can 

 be no doubt but that apple trees are more or less checked, in many situa- 

 tions, by the 'want of water during the dry times of July and August, and 

 more in- some soils and situations than others. Neither can there be any 

 doubt of a responsive activity to the effects of a warm and wet autumn. The 

 buds swell and burst into shoots or flowers in many cases, and in the south- 

 ern latitudes of Illinois are sometimes very conspicuously developed. With 

 a corresponding activity of the cambium and a subsequent hard freeze; it is 

 little wonder that damage is done. 



The evil consequence then, of the summer's drouth, is what we should in 

 the first place strive to avoid. This may be accomplished in several ways 

 known to us all, and I may only mention such as the choice of site, deep 

 drainage to favor the penetration of roots into soil likely to be moist in sum- 

 mer, good surface cultivation during dry times, extensive mulching, selec- 

 tion of varieties possessing [powers of withstanding drouth. Of these only 

 the first will be here further discussed. 



In my own region of country. Central Illinois, I have been greatly struck 

 with the comi)arative healthfulncss of apple orchards on the flat lands, while 

 upon the high ridges, usually most esteemed for fruit trees, decided unheal th- 

 fulness is the rule. In view of the foregoing, is it not probable that an im- 



