FORESTRY. 981 



ami the data presented show that the tree has actually shrunken in size since the 

 first recorded measurements. About 17<io the measurements, as reported in Evelyn's 

 Sylva, showed that at that time the circumference of the tree at the ground was 78 

 ft. and the height was 80 ft. The measurements recorded in 1774 showed that it 

 ■had attained a circumference of 81 ft. <i in., l>ut through damage by storms the lead- 

 ing branch had been torn away. Its dimensions in 1893, as measured by the author, 

 showed a girth of ~>4 ft. 3 in. at the ground, and a height, including dead wood, of 

 37 ft. An explanation of this great diminution in diameter is given in that the tree, 

 which, according to all measurements, tapered very rapidly, had through the loss 

 of many of its roots actually sunken into the ground, so that the point of measure- 

 ment at the later date was considerably above that which is recorded in the earlier 

 figures. This supposition is also supported by the fact that the distance from the 

 ground to the first principal branch has been a diminishing one. 



Various estimates have Keen made as to the age of this famous tree, but according 

 to the author it is probably about 500 years old. 



Hybrid maples, F. Pax (Mitt. Dent. Ihwlr*,!. GeseU., 1903, }>/>. 8SS7; <i>>.<. in Bot. 

 CentbL, 96 I 1904), No. 49, pp. 585, 586). — Brief descriptions are given of 12 hybrids 

 between different species of the genus Acer, and the origin of the different hybrids 

 is shown. 



The effect of constitutional vigor of forest trees on the forest crop, J. 

 Simpson i Gard. Chron., 3. ser., 36 i 1904), No. 935, pp. 362-364). — A discussion is given 

 of the relation of constitutional vigor of trees to the production of timber crops, and 

 an account presented of plantations in which trees of the same age but of different 

 vigor were planted and records kept. 



A tract of 240 acres was planted 50 years ago to larch, in which there was a careful 

 selection of vigorous trees for planting, and at the same time from the same nursery 

 lot was planted a considerable number of smaller, weaker trees. Measurements were 

 made showing that the trees having the weaker growth had continued throughout 

 to be smaller and they have produced a mixed growth of less than half the value of' 

 that produced from the selected trees. Similar results are quoted for ash ami sycamore. 



As a result of the author's investigations he recommends that for forest, as well as 

 other plantings where good growth is desired, care should be exercised in selecting 

 the trees for planting. 



Physiological investigations on the reserve materials of trees, Leclerc do 

 Sablon (Rev. Gtn. Bot., 16 (1904), Nos. 189, pp. 341-368, figs. 7; 190, pp. 386-401, 

 Jigs. 7). — A study was made of the different parts of a number of trees and shrubs 

 to ascertain the disposition and utilization of the reserve materials stored within 

 them. Roots, stems, and leaves of the chestnut, pear, quince, peach, willow, and 

 raspberry were studied, and the results are given at length. 



Among deciduous trees the roots serve as storage places for carbohydrates. The 

 maximum deposition of carbohydrate reserves is attained in the autumn. During 

 the winter the carbohydrates gradually decrease, the starch apparently heing trans- 

 formed into a form of cellulose. In April and May the reserve carbohydrates in the 

 n h its disappear entirely, heing used in the formation of new branches and new roots. 

 From June to October the supply is renewed and stored up as before. In general, 

 stems act in a similar manner in serving as storage places for reserve materials. As 

 a rule comparatively little carhohydrate reserve material is permanently stored in 

 the leaves. 



The nitrogen content of stemsand roots attainsits maximum in the autumn, varies 

 little during the winter, but attains a minimum in May or June, after which there is 

 an increase. The leaves have a relatively higher nitrogen content early in the spring 

 of the year, but the proportion falls rapidly. At the restoration of growth the stems 

 and roots give up a large proportion of their nitrogen to the newly forming leaves 

 and later receive it again as reserve nitrogen, 



