44 GENETICS [BOT. AbsTS., VoL. IX, 



273. Thiem. [German rev. of; Haeckel, Ernst, Hugo Eisig, und Karl Hescheler. 

 Aus dem Leben und Wirken von Arnold Lang. (From the life and activities of Arnold Lang.) 

 G. Fischer: Jena, 1916.] Arch. Rassen- u. Gesellschaftsbiol. 13: 311. 1921. 



274. Thomson, J. Arthur. [French rev. of: Doncaster, L. An introduction to the 

 study of cytology. 15 X 23 cm., xiv + 280 p., 24 pL, 31 fig. Cambridge Univ. Press: England, 

 1920.] Scientia 29: 233-234. 1921. [See also Bot. Absts. 7, Entries 722, 723, 842.] 



275. Thomson, J. Arthur. [French rev. of: Morgan, T. H. The physical basis of 

 heredity. 14 X 21 cm., 300 p., 117 fig. J. B. Lippincott Co.: Philadelphia, 1919 (see Bot. Absts. 

 5, Entry 422; 7, Entry 938).] Scientia 29: 235-236. 1921. 



276. ViEiLLARD, P. Note sur la selection des riz par la constitution delignees pures et 

 sur les hybridations des riz. [Note on the selection of rice by the constitution of pure lines 

 and on the hybridization of rice.] Bull. Agric. Inst. Sci. Saigon 2: 11-15. 1920.— The methods 

 of rice breeding in use at Tjikeumeuh near Buitenzorg (Java) are outlined. There are the 

 usual pure line and hybridization methods commonly employed by those engaged in work 

 on the self-fertilized cereals. The best of the pure lines have been increased and tested on 

 a large scale, showing increased yield and other desirable characters. Selections from hybrids 

 between "Skriviman Kati" and "Carolina" combine the good characters of the parents. — 

 C. E. Leighty. 



277. ViGiANi, D. Sulla selezione del frumento "Gentil Rosso." [Upon the selection 

 of the wheat "Gentil Rosso." Staz. Sperim. Agrarie Ital. 52: 5-13. 1919.- — Report on breed- 

 ing work done at Vegni Institute (Italy) on the wheat "Gentil Rosso," which is one of the 

 important varieties in Tuscany and other parts of northern Italy. It has been determined 

 by tests that this variety as commonly cultivated is less rust resistant and more liable to lodge, 

 especially on rich land, than certain other varieties, but is productive, well developed, and 

 early-maturing. Mass selection by the author resulted in increasing the yields over the vari- 

 ety as ordinarily grown. By means of pure-line breeding a strain has been developed which 

 is considered superior to Gentil Rosso; it possesses all the good characters of the latter and 

 none of its defects.- — C. E. Leighty. 



278. Vrijburg, B. Fokkerij in Indie op meer wetenschappelijke basis. [Breeding in 

 India on a more scientific basis.] Mededeel. Ver. Bevord. Wetenschap. Teelt 12. 12 p., 2 pi. 

 1921. — A general outline of breeding animals in Dutch East India is given.- — /. C. Th. Uphof. 



279. Waldron, L. R. Inheritance of rust resistance in a family derived from a cross 

 between durum and common wheat. North Dakota Agric. Exp. Sta. Bull. 147. 24 P-, 2 fig. 

 1921. — From cross between Kubanka, an amber durum, and Power Fife, a hard red spring 

 wheat of common type, certain plants of common type showed evidence of heterozygous 

 condition relative to resistance toward stem rust {Puccinia graminis). Resistance (or sus- 

 ceptibility) was found to be intermediate and evidently due to more than 1 factor. Theoret- 

 ical ratios based on 2-factor hypothesis agreed fairly well with actual results. Degree of 

 resistance in certain segregates was as much or more pronounced as in resistant Kubanka 

 parent. It is suggested that the heterozygote arose as result of simultaneous crossing over 

 engaging 2 pairs of chromosomes. Resistant wheat has less technical value than either parent. 

 — L. R. Waldron. 



280. Wright, Sew^all. Correlation and causation. Jour. Agric. Res. 20: 557-585. 16 

 fig. Jan. 3, 1921. — Formulae arc derived to measure the direct influence of one variable on 

 another assuming that the direct influence of the given variable on the other can be measured 

 by the standard deviation remaining in the effect after all other extraneous influences are 

 eliminated. The expression (ta.x is used for the standard deviation of X due to A. Path 



