92 BULLETIN 934, U. S. DEPARTMENT OF AGRICULTURE. 
(16) Beowx, William. 
1916. Studies in the physiology of parasitism. III. On the relation 
between the " infection drop " and the underlying host tissue. In 
Ann. Bot., v. 30, no. 119, p. 399-406. 
(17) Bruchmann, H. 
1885. Das Pro thallium von Lycopodium. In Bot. Centbl., Bd. 21, 
No. 10, p. 309-313. 
(18) Bryant, Arthur. 
1871. Forest Trees for Shelter, Ornament, and Profit . . . 247 p., 
[12] pi. New York. 
(19) Buckingham. Edgar. 
1904. Contributions to our knowledge of the aeration of soils. U. S. 
Dept. Agr., Bur. Soils Bui. 25, 52 p. 
(20) Burger. O. F. 
1913. Lettuce drop. Fla. Agr. Exp. Sta. Bui. 116, p. [25]-32, 3 fig. 
(21) BURGSDORF, FRIEDRICH AUGUST LUDWIG VOX. 
1783. Versuch einer vollstandigen Geschichte vorziiglicher Holzarten 
. . . Bd. 1, Theil 1. Berlin. 
(22) Busse, W., Peters, L., and Ulrich, P. 
1911. Ueber das Yorkommen von Wurzelbranderregern im Boden. In 
Arb. K. Biol. Anst. Land- u. Forstw., Bd. 8, Heft 2, p. 260-302. 
( Untersuchungen fiber die Krankheiten der Bliben, von Yv\ Busse. 6.) 
Butler, E. J. 
(23) 1907. An account of the genus Pythium and some Chytridiacese. 
In Mem. Dept. Agr. India, Bot. Ser., v. 1, no. 5, 160 p., 10 pi. 
Literature, p. 142-147. 
(24) 1913. Pythium debaryanum Hesse. In Mem. Dept. Agr. India. Bot. 
Ser., v. 5, no. 5, p. 262-267, pi. 5. (Studies in Peronosporacese, by 
E. J. Butler and G. S. Kulkarni.) 
BUTTNER, G. 
(25) 1903. Uber das Absterben junger Nadelholzpflanzen im Saatbeete. In 
Mitt. Deut. Dendrol. Gesell., No. 12, p. 81-82. 
(26) 1906. Etwas fiber den Keimlingspilz, Fusoma parasiticum v. Tub. 
In Mitt. Deut. Dendrol. Gesell., No. 15, p. 232. 
(27) Byars, L. P., and Gilbert, W. W. 
1919. Soil disinfection by hot water to control the root-knot nema- 
tode and parasitic soil fungi. (Abstract.) In Phytopathology, v. 9, 
no. 1, p. 49. 
(28) Clinton, G. P. 
1913. Report of the botanist, 1911 and 1912. In Conn. Agr. Exp. 
Sta., 36th Ann. Rpt 1911-1912, pt. 5, p. [341]-453, pi. 17-28. 
(29) Cook. Mel T., and Helyae, J. P. 
1915. Diseases of grains and forage crops. N. J. Agr. Exp. Sta., 
Circ. 51, 8 p. 
(30) Davenport, E. 
1907. Principles of Breeding . . . xiii, 727 p.. illus. Boston, New 
York. 
(31) Dawson, Jackson. 
1885. The propagation of trees and shrubs from seed. In Trans. 
Mass. Hort. Soc, 1885, pt. 1, p. 145-166. 
