NOTES AND ABSTEACTS. 



495 



Fonnation of high protein percentage depends also on the supply 

 of nitrogen, and the amount can be increased by the use of appropriate 

 fertilizers. 



The tables at the end of the report give the percentages of some 

 hundred or more individuals of each of the four races, and for every 

 year from 1897 to 1906. They appear to be of great value for the 

 study of heredity by biometrical methods. — G. F. S.-E. 



Insect Depredations in North American Forests and Prac- 

 tical Methods of Prevention and Control. By A. D. Hopkins, 

 Ph.D. {U.S.A. Dep. Agr., Bur. Entom., Bull. 58, part v.; Dec. 4, 

 1909). — There is conclusive evidence that insects have been in the 

 past, and are now, important factors in the waste and reduction of 

 timber supplies, and will continue to be such in the future (pp. 57-58). 



They attack perfectly healthy trees and kill them (pp. 58). They 

 reduce the value of living timber and that of both crude and finished 

 products (pp. 60-66). 



The results of extensive investigations and of practical applications 

 during recent years have demonstrated that some of the most destruc- 

 tive insect enemies of American forests can be controlled and serious 

 damage prevented with little or no ultimate cost over that involved 

 in good forest management and business methods. — V. G. J. 



Insecticides and Fung-icides. By A. B. Cordley (U.S.A. Exp. 



Stn., Oregon, Bull. 108; April, 1910). — Formulee and brief directions 

 for the preparation of sprays for various agricultural and domestic 

 purposes. — V. G. J. 



Insects Injurious to Truck Crops. By F. H. Chittenden, 

 Sc.D. {U.S.A. Dep. Agr., Bur. Entom., Bull. 82, part ii. ; Nov. 30, 

 1909; 6 figs.). — In this bulletin the author describes the life-history, 

 food-plants, distribution and means of prevention and extermination of 

 (1) the parsnip leaf miner, (2) the parsley stalk weevil, and (3) the celery 

 caterpillar. — V. G. J. 



Irrigration in Wyoming", Farming* without. By J. D. Tomar 

 {U.S.A. Exp. Sin. Wyoming, Bull. 80; March 1909).— A thoroughly 

 practical account of the precautions necessary and methods which 

 should be followed in " dry land farming " in this State is given. 

 There is a careful description of the meteorological conditions and 

 climate of Wyoming. Letters from many farmers who have experi- 

 mented with the dry method are included. Crops have been grown 

 with a rainfall of less than ten inches. — G. F. S:-E. 



Juniper, Fertilization of {Beih. Bot. Cent. xxv. 1. Abt. Heft ii. 

 pp. 201-241; with 4 figs, and 10 plates; 1910).— Mr. Nichols (Yale 

 University) has examined Juniperus communis var. depressa. 



Pollination occurs about May 25, and fertilization occupies some 

 12| months. There is a full description of the cytology of the arche- 

 sporium, of the formation of microspores and megaspores, of the 



K K 2 



