No. 1, May, 1921] FORESTRY 25 



187. Petrini, SvEN. Nagra sympunkter pa variations — och korrelationsrakningar. [Notes 

 regarding variation and correlation calculations.] Skogsvdrdsforeningens Tidskr. 17: 23Sx- 

 243x. 1919. — A reply to criticisms by L. Mattsson Marn of Petrini's investigations on the 

 use of the "form-point" method in determining form-class and volume. — G. A. Pearson. 



188. Petrini, Sven. Formhojdstillvaxten i tallbestand inom Vasterbottens Lan. [Incre- 

 ment per cent of the form-height in pine stands in Sweden.] Meddel. Statens Skogsforsoksanst. 

 16: 184-187. Fig. 1. 1919. — Volume increment per cents are calculated from the basal area 

 increment per cent and the "form-height" increment per cent. The latter term expresses 

 the product of height and form factor. If tables of "form-height" increment per cent are 

 available the increment per cent may be ascertained by merely measuring diameters. Jonson 

 has prepared such tables for pine in middle Sweden. Petrini, following Jonson's procedure, 

 has prepared similar tables for northern Sweden, where the pine has a different form. The 

 method which is briefly described involves the measurement of heights and the determination 

 of "mean form class" by means of the "form-point" and Jonson's function between "form- 

 point" and "form-class." — G. A. Pearson. 



189. Petrini, Sven. Om formpunctsbedomning. [The "form-point" as an expression 

 of trunk-form.] Meddel. Statens Skogsforsoksanst. 16:164-183. Fig. 1-5. 1919.— The 

 investigation aims to test the accuracy of Jonson's "form-point" method of estimating 

 volume and taper when applied to different stands and individual trees, and also the varia- 

 tions in results obtained by different persons. Estimates were made on 54 sample plots each 

 having an area of 0.6 acre. On 10 of the plots the "form-point" was determined by 6 different 

 persons. Estimates for single stands show an average deviation of ± 4 per cent of the 

 height of the tree. The average personal error for a stand was 1.17 per cent. Estimates of 

 individual trees by different persons varied as much as 10 per cent. The author concludes 

 that the "form-points" of single trees can not be estimated with any great degree of accuracy, 

 but that the average "form-point" of a stand can be satisfactorily determined. — G. A. 

 Pearson. 



190. PiNCHOT, G. Pennsylvania chestnut trees to be sold to save timber left by blight. 

 Amer. Nut Jour. 12: 91. 1920. — For the last 15 years all efforts to control blight have failed. 

 The removal of trees for use as timber is proposed. — E. L. Overholser, 



191. Rao, B. I. Shama. Note on the artificial raising of bamboos in the Akola division of 

 the Berar Circle, C. P. Indian Forester 46:518-525. 1 pi. 1920. — Bamboo has been suc- 

 cessfully introduced by sowing and planting in the Central Provinces. Watering and cul- 

 tivation are helpful to both seedlings and transplants, but the latter may succeed with little 

 outside assistance if under a high cover as in the forest. Grazing and fire are destructive 

 and must be prevented in areas recently planted. — E. N. Munns. 



192. Richards, Edward C. M. Forest conditions and primitive forest practice in West 

 Persia. Jour. Forestry 18:710-718. 1920. — Zoroastrianism, or fire worship, before the 

 Moslem conquest of Persia is responsible for great ash heaps where the ancient Parsees kept 

 the eternal fires of their shrines burning, and these ash heaps are probably the remains of the 

 former forest. Though the people are dependent on the water supply to keep their lands 

 productive, the lack of a forest cover in the mountains is not appreciated and crop failures 

 and famines are frequent. Fuel woods are scarce and nearly all bushes and weeds are gath- 

 ered for fire. In scattered places and at considerable distances from habitations, junipers, 

 almonds, and haws M'ere found growing naturally without irrigation. Poplar is the chief 

 tree and is kept trimmed down to a small top so that it forms a long slender pole. The wood 

 is the chief supply of the country. Willows growing along water courses are used for fuel and 

 water pipes. Pollarding and coppicing is the rule, cutting every three years. Other trees of 

 value are the plane, elm and walnut. Persia is in great need of forestry but the political 

 situation is such that it is as j'et far off. — E. N. Munns. 



