No. 2, March, 1921] FOREST BOTANY AND FORESTRY 117 



798. Johnston, I. M. The flora of the pine belt of the San Antonio Mountains of southern 

 California. Plant World 22:71-90, 105-122. 2 fig. 1919.— See Bot. Absts. 6, Entry 1521. 



799. JoLTET, A. Les bassins d'epuration du Wacken k Strasbourg et I'elevage des Cyprin- 

 ides. [The purification basins at Strassburg and the breeding of Cyprinides.] Rev. Eaux et 

 Forets 58: 195-202. 1920.— The problem of sewage disposal has been solved at Strassburg 

 by the construction of stagnant ponds in which the organic material is assimilated bj'^ proto- 

 zoans, worms, crustaceans, insect larvae, molluscs, etc., and these in turn are eaten bj' carp 

 and other fish. The latter are entirely safe for human consumption and have no disagreeable 

 taste. One hectare of pond is sufficient to dispose of the sewage from 2000 to 3000 people 

 (nearly ten times as many as can be cared for by filtering the waste water in settling basins), 

 and at the same time to support an abundant population of fish. This method suggests to 

 foresters the possibility of introducing organic" matter into the many ponds and streams fo'ind 

 in the plains where <'.ommunal forests cover more than 20 per cent of the land area, and of 

 using these for the breeding of carp and other Cyprinides, which would form an important 

 addition to the food supply of the country. — S. T. Dana. 



800. K., S. L. The resin industry: utilization of sand wastes. Australian Forest. Jour. 

 3: 172-175. 1920. — A brief discussion of the resin industry, and a short description of the 

 methods of collecting and refining resin.— C. F. Korstian. 



801. Lecomte, Henri. Sur la "structure etagee" de certains bois. [On the "storied 

 structure" of certain woods.] Compt. Rend. Acad. Sci. Paris 170: 705-709. 1920.— See Bot. 

 Absts. 6, Entry 1901. 



802. Ledermann, C. Einiges von der Kaiserin-Augusta-Fluss Expedition [New Guinea.] 

 [Notes on the Empress Augusta River Expedition.] Bot. Jahrb. 55 (Beiheft) : 33-44. 1919.— 

 See Bot. Absts. 6, Entry 1508. 



803. Marti, F. Verbauungen, Aufforstungen und Berasungen in den Einzugsgebieten 

 der Wildbache. [Damming, afforesting, and sodding the watersheds of the forest lakes.] 

 Schweiz. Zeitschr. Forstw. 71 : 230-244. 1920.— The forest and alpine lakes are a heritage of 

 nature, and the forest life and development often depend on their preservation. Where the 

 watersheds are barren rock or open slopes, the run-off is so rapid that the precipitation 

 causes sudden rising of the lakes and overflowing with resultant damage to the lower valleys. 

 Between the timber line and snow line there is usually an area of barren slopes from 1,000- 

 1,500 m. beginning at an elevation of 1,600-1,800 m. The forests have extended to high alti- 

 tudes, but the natural forest conditions must not be interfered with, or the timber line will 

 be brought to lower levels. The principal species are the larch and cembra pine. In some 

 localities, large areas of young growth are dying, although the underplanted spruce remains 

 thrifty. Afforestation may be effective in some regions, depending on temperature and pre- 

 cipitation. Wide variations of precipitation occur on different slopes due to direction of storm 

 movements and ridges. Where afforestation is not practicable, the areas should be sown to 

 grass to prevent erosion. In some regions it is necessary to build terraces. Where rock is 

 available it affords the best material for construction, but sod and a mixture of dirt and 

 gravel may also be used. — J. V. Hofmann. 



804. McLean, R. C. Studies in the ecology of tropical rain forests, with special refer- 

 ence to the forests of South Brazil. Jour. Ecoj. 7: 121-172. 10 fig. 1919.— See Bot. Absts. 6, 

 Entry 1500. 



805. Mill, R. H. Woods and water supply. [Rev. of: Henry, Augustine. Forests, 

 woods and trees in relation to hygiene. XII + 314 p. Constable and Co.: London, 1919.] 

 Nature 105: 158-159. 1920.— Greater part of volume is devoted to afforestation of water 

 catchment areas. Reviewer agrees with author that the effect of afforestation in increasing 

 the general rainfall is probably negligible in the British Isles. — 0. A. Stevens. 



