1920] CURRENT LITERATURE 163 



considered to be a fruiting spur for the season in which it bloomed. It might 

 be questioned whether the author was justified in making such an assumption. 



Jonathan, Winesap, and Grimes were found to produce a fair amount of 

 bloom each year, but with no exceedingly productive seasons; while Rome, 

 York, and Gano were found to have a very high percentage of bloom one sea- 

 son and a comparatively low one the next. Winesap and Jonathan, in the 

 order named, were able to develop blossoms in successive seasons on the 

 same spur in a much greater proportion than the other varieties. The dif- 

 ference between alternating and non-alternating varieties seems to be due to 

 the ability of the spurs of the regular bearing kinds to blossom two years in 

 succession. The most effective fruiting age for the spurs, irrespective of the 

 type of bearing, appeared to be from 3 to 7 years. 



Determinations of the relative amounts of food reserve in the fruit spurs 

 were made by finding the lowering of the freezing point in the spur sap by 

 means of a Beckman apparatus. Only relative proportions of reserves were 

 indicated by the lowering of the freezing point, and starch not at all. It was 

 found that sap from the bearing spurs had a slightly higher concentration 

 during a considerable portion of the year than sap from non-bearing spurs. It 

 must be remembered, however, that the method of analysis gave no indication 

 of the amount of starch that might have been present. It was found that 

 during the latter part of June and early July there was a sudden drop in con- 

 centration of sap, both in fruiting spurs and non-fruiting spurs, and at that 

 time both kinds of spurs reached a similar degree of concentration. The 

 author concluded also that little difference in concentration of the cell sap 

 could be attributed to soil conditions or to the number of fruits being produced 

 upon a spur. 



Chemical analysis of the spurs of Yellow Transparent were made in order 



to ascertain the amounts of sugars and starch stored. It was found, in the 

 majority of cases, that there was a slightly greater amount of sugar, both 

 reducing and total, in the non-bearing spurs. The starch content of the non- 

 bearing spurs did not average quite so high as that of the bearing spurs, but 

 there was considerable variation in these results. Inasmuch as the determina- 

 tions made were comparatively few in number (22) and covered only the 

 period from late October to April, no conclusions were drawn. A determina- 

 tion of nitrogen would have made this work much more valuable. 



It was found that non-bearing spurs had a larger total leaf area than 

 bearing spurs, and that the difference was due more to the number of leaves 

 than to the size of the individual leaves. 



The effects of girdling upon the concentration of cell sap were determined 

 by noting the depression of the freezing point. The sap of all parts above the 

 girdle was found to have an increased concentration, and the sap of ail parts 

 below the girdle a decreased density when compared with sap from correspond- 

 ing parts of similar but ungirdled trees. The greatest effect was observed 

 upon the sap of the trunk, and the difference became less as the distance from 



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