No. 3, April, 1921] GENETICS 267 



1844. TisCHLER, G. [German rev. of: Sakamura, T. Experimentelle Studien iiber die 

 Zell- und Kernteilung mit besonderer Riicksicht auf Form, Grosse und Zahl der Chromosomen. 

 (Experimental studies on cell and nuclear division with special reference to form, size, and 

 nimiber of the chromosomes.) Jour. Coll. Sci. Imp. Univ. Tokyo 39": 1-221. 7 pi., 24 fig. 

 1920.] Zeitschr. Indukt. Abstamm. u. Vererb. 24: 183-184. Sept., 1920. 



1845. TiscHLER, G. [German rev. of: Schacke, Martha A. A chromosome difference 

 between the sexes of Sphaerocarpos texanus. Science 49: 218-219. Feb. 28, 1919. (See Bot. 

 Absts. 3, Entry 1034.)] Zeitschr. Indukt. Abstamm. u. Vererb. 24: 183. Sept., 1920. 



1846. TiscHLER, G. [German rev. of: Winge, 0. On the relation between number of 

 chromosomes and nimiber of types, in Lathyrus especially. Jour. Genetics 8: 133-138. PL 5. 

 April, 1919. (See Bot. Absts. 3, Entry 306.)] Zeitschr. Indukt. Abstamm. u. Vererb. 24: 

 182. Sept., 1920. 



1847. VON Tschermak, E. Steigerung der Ertragsfahigkeit der Tomaten durch Bas- 

 tardierung in der ersten Generation. [Increase of productivity of tomatoes through hybridiza- 

 tion in the first generation.] Nachr. Deutsch. Landwirtschaftsges. f. Osterreich 1918: 425-426. 

 1918. — 'Author recalls work of Shxjll and of East and Hayes on maize wherein poor strains 

 secured by inbreeding gave rise on crossing to good Fi plants. Points out also similar valu- 

 able results in case of Fi in some domestic animals. Brief report then given of results on four 

 varieties of tomatoes. Most fully investigated were Cooper's First Crop andFicarazzi, the 

 former of which yielded per plant an average of 3.6 kgm., the latter 3.0 kgm. The Fi hybrids 

 of these two varieties yielded over 5.1 kgm. per plant (based on 16 plants). Because of 

 ease of securing hybrid seed author deems its production for commerce as worth considering. 

 — -James P. Kelly. 



1848. Urban, J. Die Grosse der Riibenknauel und der Riibenertrag. [Size of the beet 

 seedballs and yields of beets.] Zeitschr. Zuckerind. Cechoslovak. 44: 151-155. 1920.— See 

 Bot. Absts. 7, Entry 1714. 



1849. Vernet, G. Biometrie et homogeneite. [Biometry and homogeneity.] Bull. 

 Agric. Inst. Sci. Saigon 2: 15-26. 1920. — 'The author discusses some of the precautions neces- 

 sary in interpreting distribution curves. He considers it impossible to determine the com- 

 ponents of a bimodal or other composite curve. He suggests that the representation of dis- 

 tribution curves be standardized as to number of individuals, scale of ordinates and abscissas 

 to be used in each variety of plant or animal. — Sewall Wright. 



1850. Walther-Giessen. [German rev. of: Kuiper, K., Jr. Onderzoekingen over 

 kleur en teekening bij runderen. Naar experimenten van R. Houwink Hzn. (Researches on 

 color and markings in cattle. Based on experiments by R. Houwink Hzn.) Genetica 2: 137- 

 161. 5 pi. Mar., 1920. (See Bot. Absts. 6, Entry 1096.)] Zeitschr. Indukt. Abstamm. u. 

 Vererb. 24: 292-293. Nov., 1920. 



1851. Walther-Giessen. [German rev. of: Little, C. C. A note on the himian sex ratio. 

 Proc. Nation. Acad. Sci. [U. S.] 6: 250-253. 1 fig. May, 1920.] Zeitschr. Indukt. Abstamm. 

 u. Vererb. 24: 296. Nov., 1920. 



1852. Wilder, Harris Hawthorne. Physical correspondences in two sets of duplicate 

 twins. Jour. Heredity 10:410-420. Fig. 15-19. Dec, 1919.— The author points out that 

 there is a comparable degree of similarity of palmae and plantar ridges between duplicate 

 twins as between the rows of scales of the carapace of a single litter of armadillos. Since 

 Newman and Patterson have shown that the armadillo is polyembryonic, we may assume 

 that duplicate twins are polyembryonic. After discussing briefly the palm and sole prints of 

 duplicate and fraternal twins, the author presents the measurements and prints of two sets 

 of duplicate twins which show remarkable similarity between the individuals of a twin group 

 and the lateral symmetry of a single individual.^/. H. Beaumont. 



