1010] FOKESTRY. 47 



to the previous flora of these moors, inasmuch as the pollen may have been 

 curried from long distances. 



Anatomy of the union of a spruce graft on pine, L.-G. Romell {Meddel. 

 ,^t.:it. Skoysfvrsoksanst., No. 16 {1919), pt. 2-3, pp. 61-66, figs. 2).— The author 

 describes a case of natural grafting of spruce on pine, and discusses anatomical 

 peculiarities observed in the region of the union. A brief bibliographical para- 

 graph of cited literature is appended. 



From a study of the graft as a whole it is concluded the foreign cells, 

 though to a large extent autonomously reacting in a morphological sense, react 

 physiologically with eacli other in a thoroughly harmonious way as parts of 

 a single organism. 



A study of the frustum form factors of hard maple and yellow birch., 

 B. A. Chandler {rermont Sta. Bui. 210 {1918), pp. 3-38, figs. 8).— During the 

 course of timber-estimating v\ork on the State forests of Vermont and else- 

 where from 1912 to 1017, the author found that volume tables based alone on 

 diameter and height measurements gave thoroughly unsatisfactory results. 

 Frustum form factors were computed from measurements of a few yellow 

 birches and hard maples and applied to a table of frustum volumes, based on 

 a local top diameter curve. In view of the more satisfactory results obtained 

 by this preliminary application of the frustum form factor, the work was 

 greatly extended in 1915 and 1916, measurements being made of over 1,200 

 trees, principally yellow birch and hard maple. Frustum form factors were 

 constructed from these measurements and were studied chiefly to determine 

 the laws which govern the frustum form and methods of expressing them. 

 The results of the study are discussed in detail, and the application of the 

 frustum form factor to practical timber estimating is described. A bibliog- 

 raphy of cited literature is given. 



Formulas were developed from the study to find the value of the absolute 

 diameter breast-high frustum form factor in terms of the taper ratio and 

 form quotient ; the value of the absolute diameter breast-high cylinder form 

 factor in terms of the frustum form factor and taper ratio ; the value of the 

 cylinder form factor, when the section below diameter breast high is computed 

 as a cylinder, in terms of the absolute diameter breast-high frustum form factor 

 and taper ratio ; and the value of the absolute diameter breast-high cylinder 

 form factor in terms of form quotient and taper ratio. 



The method of obtaining the form-class and volume of single trees by the 

 use of form-point. — An investigation based on spruce material from Norr- 

 botten, Sv/eden, S. Petrini {Meddel. Stat. Skogsfdrsoksanst., No. 15 {1918), 

 pp. 233-273, XXIX-XXXII, figs. 9; Skogsvdrdsfor. Tidskr., No. 11-12 {1918), 

 pp. 597-635, figs. 9). — In the investigation here reported, measurements were 

 made of spruce material from forests differing in age, height, density, quality of 

 soil, etc., in order to determine the degree of accuracy of the form-point method in 

 determining the volume of individual standing trees. 



It is concluded that the form-point method can not be used with sufficient 

 accuracy for single trees, because the form-class is determined only as an 

 average value applicable to the whole material. 



Results of cutting at Ne-Ha-Sa-lSTe Park, in the Adirondacks, B. A. 

 Chandler {Jour. Forestry, 17 {1919), No. 4, pp. 378-385, figs. 5).— Data are 

 given of spruce growth and reproduction on lands cut over for spruce some 15 

 to 20 years ago. 



The results of the study as a whole indicate that, on hardwood lands man- 

 aged for spruce, as much of the hardwoods should be cut as market conditions 

 wiU allow, and the maximum number of small and medium, well-topped, free 



