FORESTRY. 645 



Planting" methods as a means of preventing the attack of the May beetle, 

 D. TiEMANN (Forstiv. CenlbL, n. ser., 32 (1910), No. 2, pp. SJ,-<)1). — The author 

 calls attention to the general recommendation that in establishing forest planta- 

 tions the soil should be loosened as little as possible in order to render con- 

 ditions unfavorable for the breeding of May beetles. He points out that 

 the ball method of planting trees more nearly approaches this condition 

 tlian any other, and outlines and discusses a series of planting experiments 

 which might throw some light on the relative efficiency of different methods 

 of planting in combating the insect. 



Forest production, C. Girerd (Semainc Agr. [Paris]. 29 {19 tO), Xo. U',91, 

 pp. JfJi-Jil). — The author reviews the present status of forest production in 

 France and discusses tlie need of increased forest areas. 



The productivity of woodland soil, J. Nisbet (Nr/. Prog. Twentieth Cent., 

 /; {1910), Xo. /■), /*/*. oOJi~olO). — The importance of humus in the maintenance 

 of forest growth is iioiuted out and it is stated that "the best method of insur- 

 ing a humus favorable to soil productivity is to grow timber crops in mixed 

 woods consisting of kinds of trees suitable to the soil and situation, and cai)able 

 of protecting the soil against the deteriorating effects of sun and wind; and in 

 such mixed woods the beech has on the Continent been found to possess the 

 most valuable properties regarding the conservation and the increase of soil 

 productivity." 



Experiments in tapping Ceara rubber trees, E. V. Wilcox {Hawaii Sta. 

 Bui. 19, pp. 7-20). — In continuation of initial experiments with the Ceara rub- 

 ber tree in Hawaii previously noted (E. S. R., 20, p. 245) the results are given 

 of one year's experiments which were undertaken to demonstrate the yield of 

 latex from Ceara rubber ti-ees and to determine their commercial possibilities, 

 as well as to study the relative value of different methods and times of tapping 

 and the possibility of utilizing local Jai)anese labor in the work of tapping and 

 collecting rubber. The work was conducted cooperatively by the station and 

 the territorial division of forestry, in conjunction with the directors of 4 private 

 rubber i)lantations. 



Although it is generally recommended that trees should not be tapped until 

 they are 6 to S years old, the majority of the trees tapped in the experiments 

 were only 2 or 3 years old. One series of 80 trees was tapped by means of one 

 vertical cut each day, the cut being about 7 ft. in length and extending from the 

 gi'eatest height the laborers could reach to a point near the ground. It re- 

 quired 36 hours and 40 minutes of labor to tap the trees, collect the latex and 

 secure by coagulation 1* lbs. of rubber, but with exi)erience this time was 

 greatly reduced. Another series of 160 trees which were tapped with 2 vertical 

 cuts in place of 1, required only 40 hours of labor and yielded 5 lbs. of prime 

 rubber and 2i lbs. of scrap rubber, and gave profitable returns. 



Tapping experiments made on some mature Ceara trees indicate that about 

 i oz. of dry rubber may be expected as a daily yield from each tree. From the 

 data at hand, it is estimated conservatively that the Ceara rubber tree will 

 not only grow and thrive in the Territory but will yield profitable returns. 



With trees 4 in. in diameter, single vertical cuts can be made daily for 2 

 weeks in succession or 2 vertical cuts daily for 1 week. Comparisons of the 

 " V " cuts with vertical cuts resulted in favor of the vertical cut as to yield, 

 although there appears to be no difference between the two in the healing of 

 the bark wounds. 



The results as to time of tapping show the yield to be somewhat larger about 

 daylight than at any subsequent time, the difference, however, being more 

 noticeable on clear days with the bright sun than on cloudy cool days, when the 



