372 STATE POMOLOGICAL SOCIETY. 



ume of "Proceedings of American Association") that trees of the strongest 

 constitutions leaf tlic earliest. Thus there are varying times of leafing in 

 Xorway sjiruces. though both be of one age. In a severe winter, if one or two 

 sucli die, it will be the one which leafs tlie latest. Tlie early one is the hardiest. 

 Now a young tree is always more tender than one approaching a liowering con- 

 dition. Young trees are often destroyed when older ones escape. This being 

 the case, there would be a difference in the time of leafing between such voung 

 ones and their elders. On the other hand, wliere young trees had as strong a 

 constitution as older ones, and there may be many such cases, there would be 

 little difference. 



WHERE DOES THE SAP WIXTEK? 



The generally accepted theory in regard to the circulation of saj) in trees is 

 that it flows down from the limbs to the roots in the autumn, where it remains for 

 the winter. In the spring it flows upward to the limbs again, to aid in the re- 

 production of leaves, blossom.-?, and fruit. I do not know that I have ever 

 heard this theory disputed, until recently. But now it has not only been dis- 

 puted, but proved false by experiments made at the Massachusetts Agricultural 

 College. 



The experiments were as follows : In December a maple tree was cut off 

 near the bottom, and still so fastened that it remained upright. Tiie trunk 

 was sealed over with wax. Thus the tree stood until spring, when it was 

 topped, and the result was the sap flowed as freely as from other trees, which 

 had not been cut off. Of course the sap in this case could not flow from the 

 roots, as the tree had been entirely cut off for several months. It must have 

 come directly from the body and limbs, and hence it must have remained there 

 all winter. 



Another experiment : A young maple was cut in the winter, and carried 

 into the greenhouse, and after it had ''thawed out" it was topped. The sap 

 at once began to flow, and continued for thirty-six hours. The tree was then 

 taken out and allowed to freeze again. Upon being carried back into the warm 

 greenhouse, the sap resumed its flow, and continued to do so as long as the 

 freezing and thawing processes were kept up. This experiment confirms the 

 fact established by the other just related, that the sap of trees docs not winter 

 in the roots, but in the tree as a whole, and in every part of it; and that the 

 freezing and thawing are the only conditions of preventing and causing the sap 

 to run. 



One more experiment should be tried, if it has not been, viz. : to top the 

 roots of the tree in the spring, after the trunk has been removed. I have no 

 doubt it would Ije found that the sap would flow as freely from the roots as 

 from the trunk. The following fact Avould seem to substantiate this opinion. 

 Last March a yellow birch tree was cut in the woods, in the process of gather- 

 ing fuel. And it was observed a month later that the sap flowed from the- 

 stump copiously. This fact alone would go to prove the old theory that the 

 sap of trees winters in the root> ; l)ut tlie otlier experiments above cited, show 

 that it winters also in the body and limbs. 



On the whole, we are forced to the conclusion, that the old theory is false, 

 and that the sap of every tree permeates the branches, body and roots, in the 



