1918] ECONOMIC ZOOLOGY ENTOMOLOGY. 457 



Handbook of birds of the western United States, including the Great 

 Plains, Great Basin, Pacific slope, and Lower Rio Grande Valley, Florence 

 M. Bailey (Boston and New York: Houghton Mifflin Co., 1917, 7. ed., rev., 

 pp. LI +574, pis. 33, figs. 601). — A revised pocket edition of the work previously 

 noted (E. S. R.. 14, p. 551). 



Notes on North American birds, H. C. Obekholser (Auk, 34 {1917), Nos. 2, 

 pp. 191-196; 3, pp. 321-329; ),, pp. J,65-i70). 



Notes on the genus Puffinus, H. C. Obekholser (Auk, 34 (1917), No. 4, PP- 

 471-475). 



The shedding of the stomach lining by birds, particularly as exemplified 

 by the Anatidae, W. L. McAtee (Auk, 34 (1917), No. 4, pp. 415-421, pis. 2). 



The food of nestling birds, H. E. Enders and AV. Scott (Proc. Ind. Acad. 

 Sci., 1915, pp. 323-337; abs. in Auk, 34 (1917), No. 4, pp. 494. ^95).— This is a 

 report of field studies of the number of feedings of broods of the brown 

 thrasher, robin, wood pewee, and kingbird and the general nature of their food. 



English sparrow (Passer domesticus) feeding on the larva of the elm-tree 

 beetle, N. E. Wilmot (Auk, 34 (1917), No. 4, pp. 479, 480).— In addition to 

 feeding on the elm-tree beetle in large numbers on the trunks of trees, the 

 author observed the English sparrow to feed upon small moths on the wing, 

 May beetles, etc. He is of the opinion that this sparrow is becoming more 

 insectivorous each year. 



[The attraction and protection of birds], E. H. Forbush (Agr. of Mass., 

 1916, pt. 2, pp. 191-263, pts. 7, figs. 10).— A discussion (1) of the food plants 

 that attract birds and protect fruit, including diagrams taken from Farmers' 

 Bulletin 621, previously noted (E. S. R., 32, p. 347), which show the seasons 

 of fruits attractive to birds and of fruits useful to protect cultivated varieties, 

 and (2) of the natural enemies of birds as previously noted (E. S. R., 38, p. 54). 



Hydrocyanic acid gas as a soil fumigant, E. R. de Ong (V. S. Dept. Agr., 

 Jour. Agr. Research, 11 (1917), No. 9, pp. 421-436, pi. 1. fig. i).— This is a 

 detailed report of investigations conducted at the California Experiment Sta- 

 tion, the results of which have been summarized as follows : 



" The toxicity of hydrocyanic acid gas solutions varied with the insects ex- 

 perimented upon, from the minimum for house flies of 0.0156 gm. of sodium 

 cyanid per liter (equivalent to 0.0046 per cent of hydrocyanic acid gas over 

 the solution) to the maximum for beetles of 0.125 gm. sodium cyanid per liter 

 (equivalent to 0.0365 per cent of hydrocyanic acid gas over the solution), the 

 latter being the most resistant of any insect experimented upon. Gas from 

 a solution of approximately the same strength as that used above on house flies 

 retarded the germination total of lettuce seed 11.3 per cent. Lettuce seed is 

 not killed by two days' exposure to hydrocyanic acid gas as strong as 0.0366 

 gm. of sodium cyanid per liter (equivalent to 0.0109 per cent of hydrocyanic 

 acid gas over the solution) and will give a good germination percentage if 

 removed at the end of this time. 



" Stimulation was greatest at a point one-sixteenth of that causing retarda- 

 tion, namely, 0.0011 gm. of sodium cyanid per liter (approximately 0.00033 per 

 cent of hydrocyanic acid gas over the solution). 



" Solutions of hydrocyanic acid gas approximately 256 times as strong as 

 that necessary to produce gas having the minimum killing strength for flies 

 were fatal to all seedlings tested and to 50 per cent of the cuttings placed in the 

 solution, while a solution approximately twice as strong as that required to 

 produce a gas concentration fatal to flies had no effect even upon seedlings. 



" Sodium cyanid solutions introduced into the soil failed to give a trace 

 of hydrocyanic acid gas in air drawn from the soil. The use of pressure in 



