842 EXPERIMENT STATION RECORD. [Vol.36 



raulched-basin system to produce response in the tree growth. The new leaves 

 on the basined trees were larger and darker in color and had a better texture 

 than those on the unbasined trees, especially on heavy soil. Likewise, the 

 new growth of rootlets was better under the mulch in the basins, and the 

 quality of the fruit on the basined trees was superior to that of the unbasined 

 trees. 



The experiments indicate that alfalfa and bean straw are superior to stable 

 manure for mulching purposes. In addition to producing a measurable in- 

 crease in the humus content of the soils, the use of an organic mulch moderates 

 the rise in soil temperature during the day and aids in conserving moisture. 



The authors suggest that surface mulching with organic material, especially 

 when available in quantities sufficient to cover the entire surface, may in the 

 long run prove fully as effective as the use of the mulching material in basins. 

 The mulched basin, however, brings about the incorporation of humus more 

 quickly than organic mulches with furrow irrigation, and it also appears to 

 be the most effective means of using a limited quantity of mulching material. 



In view of the successful results in the experimental tracts the mulched- 

 basin system is recommended for experimental consideration by citrus growers 

 as compared with other systems in commercial practice. 



The mulch basin system, L. J. Bkiggs, C. A. Jensen, and J. W. McLane 

 iCal. Citrogr., 2 (1917), No. 5, pp. 11, 12, fig. 1). — A summary of the above. 



A humidifier for lemon curing rooms, A. D. Shamel (U. S. Dept. Agr. Bui. 

 494 {1911), pp. 10, figs. 7). — This bulletin describes the plan of work used in 

 conducting humidity studies in some lemon-curing rooms in southern California, 

 summarizes the results noted in a previous paper (B. S. R., 36, p. 741), and 

 describes and illustrates the arrangement and structure of a humidifier invented 

 by the author in 1914 for use in maintaining conditions of uniform humidity 

 in lemon-curing rooms. 



The humidifier has been successfully used for two seasons, both for con- 

 trolling humidity in lemon-curing rooms and for improving air conditions in 

 living rooms in private houses and elsewhere in California. 



Shade trees, characteristics, adaptation, diseases, and care, G. E, Stone 

 (Massachusetts Sta. Bui. 170 (1916), pp. 12S-264, figs. 110).— A practical 

 treatise covering the various questions relative to shade trees and their man- 

 agement and superseding Bulletin 125, previously noted (E. S. R., 20, p. 643), 

 which took up the subject in a general way. 



The phases discussed include requirements of shade trees; street and road- 

 side trees ; what shall we plant ; rapidity of growth of trees ; streets and 

 avenues; distance to plant; country roadsides; root characteristics; branching 

 characteristics ; soil conditions, texture, etc. ; soil covers, lawns, macadam, 

 etc. ; excavations, curbings, and sidewalks ; effects of light and shade ; trans- 

 planting ; tree surgery ; tree guards ; fertilizing trees ; diseases of trees ; winter 

 injuries ; drought ; sun scorch and bronzing of leaves ; mechanical injuries ; 

 injurious chemical substances ; effects of illuminating gas on trees ; effects of 

 atmospheric gases on vegetation ; electrical injuries ; the spraying of shade 

 trees ; valuation of shade trees ; court decisions concerning damages to trees ; 

 and codified shade tree laws of Massachusetts, 1915. 



Ftunigation of ornamental greenhouse plants with hydrocyanic acid gas, 

 E. R. Sassceb and A. D. Borden (U. S. Dept. Agr. Bui. 513 (1917), pp. 20, figs. 

 4). — Practical directions are given for fumigating greenhouse plants with 

 hydrocyanic acid gas, including a discussion of the necessary equipment, method 

 of preparing the house and of computing the cubical contents of greenhouses, 

 time for fumigation, chemicals required, methods of mixing the chemicals and 



