No. 3, January, 1922] GENETICS 157 



1032. Anonymous. The birth rate in mixed marriages. Jour. Heredity 11: 96. 1920. — 

 Review of an article by R. E. May in Zeitschr. Sexualwiss. April, 1919. — Howard J. Banker. 



1033. Anonymous. The pollination of fruit blossoms. Gard. Chron. 66:278-279. 1919.— 

 A list is given of fertile and self-sterile varieties of apples, pears, plums, and cherries. Varie- 

 ties are listed which should be planted together. — H. K. Hayes. 



1034. AuMioT, J. Experiences de rajeunissement et de perfectionnement de la pomme de 

 terre. [Rejuvenation and improvement of the potato.] Rev. G6n. Bot. ii: 183-189, 244-263. 

 1921. — In the section on bud variations the author states that particularly for Solanum Com- 

 mersonii and S. Maglia heavy manuring and insolation are important in leading to the condi- 

 tion of non-equilibrium of the pre-mutation period. Many bud mutations are described, 

 among them one of S. Commersonii that was productive and disease-resistant, and another from 

 S. Maglia that was productive and drought-resistant. The greater part of the report deals 

 with varietal hybrids ("mdtis") and specific hybrids ("hybrides"). The former are likely 

 to show a preponderating male influence. Emphasis is laid on this "fundamental principle of 

 regeneration and improvement"; the disease-resistance, productivity, vigor, etc., of a varietal 

 hybrid may be superior to that of the better parent. The author refers to contagiousness of 

 leptonecrosis and mosaic and to their not being transmitted by seed. Starting from seed is 

 given as a method of eliminating such infections from stock. — /. P. Kelly. 



1035. Bally, W. Selectie bij rubber en koffie. [Selection in rubber and coffee.] Med- 

 edeel. Proefsta. Midden Java 33 : 22 p. 1920. — The most promising method for improvement in 

 rubber is selection of good latex-producing and disease-resistant trees and subsequent propa- 

 gation by budding. From present indications the most promising method in coffee is selec- 

 tion of healthy, productive (both in number and weight of fruit) trees and propagation from 

 cuttings or self-fertilized seed. — Helene Yampolsky. 



1036. Behrens. [German Rev. of: Yamaguchi, Yasuke. Uber die Beziehung der 

 Aufbliihzeit und des Sitzes der Bliite am Rispenaste zum korngewichte des Reises. (The rela- 

 tion of flowering time and the position of the flower on the inflorescence to seed weight in rice.) 

 Ber. Ohara Inst. Landw. Forsch. 1: 451-517. 35 fig. 1919 (see Bot. Absts. 9, Entry 1386)]. 

 Zeitschr. Bot. 13 : 603-604. 1921. 



1037. Bishop, O. F., J. Grantham, and M. J. Knapp. Field experiments with Hevea. 

 [Rev. of: (1) Bishop, O. F., J. Grantham, and M. D. Knapp. Probable error in field 

 experimentation with Hevea. Arch. Rubbercult. 1:335-364. 1917. (2) Grantham, J., and 

 M. D. Knapp. Field experimentation with Hevea brasiliensis. Arch. Rubbercult. 2 : 614-630. 

 1918 (see Bot. Absts. 10, Entry 1054). (3) Maas, J. G. J. A. Betrouwbaarheid van Veld- 

 proeven bij Hevea. (Reliability of field experiments with Hevea.) Arch. Rubbercult. 2: 

 560-607. 1918 (see Bot. Absts. 10, Entry 1068)]. Agric. Bull. Federated Malay States 6:596- 

 597. 1918. 



1038. Blakbslee, A. F. Types of mutations and their possible significance In evolution. 

 Amer. Nat. 55: 254-267. 1921. — Mutations of genes. — Only 3 of these are known in Datura 

 Stramonium after many years' observation by several workers. Experiments with Portulaca 

 grandiflora confirm the view that these mutations may arise in somatic cells. Changes in 

 chromosome number. — In 1 of the dozen or more Daturas with an extra chromosome, the pro- 

 geny behave as if the gene for purple or white color were tripled, giving the expected ratios in 

 the progeny of both heterozygotes, Aaa and AAa, after allowing for differential viability of 

 pollen-cells and zygotes. In true tetraploid plants with twice the normal group of chromo- 

 somes, the purple-white gene is quadrupled, giving the expected ratios in the progeny of each 

 of the 3 heterozygotes, Aaaa, A Aaa, and A AAa. These genetic results, together with the 

 observations on the chromosomes, afford a proof of the chromosome theory of heredity for 

 flowering plants. Apparently the segregation of dwarf forms from the tetraploid form of 

 Oenothera Lamarckiana in the cultures of de Vries occurred in the expected ratios, after allow- 



