June, 1920) GENETICS 305 



2080. A.8TLET, llrnKur I). Hybrid Barraband and Queen Alexandra Parrakeets. Avic. 

 Mag. 10: 212-213. 1919.- Polytelia Alexandras 9 mated to /'. barrabandi d" produced two 

 young, favoring the father in coloring. Both died before mature plumage was attained. — 

 J. L. Collins. 



2081. Batkkon, \\\, and Ida Sutton. Double flowers and sex linkage in Begonia. Jour. 

 Genetics 8: 199-207. PL 8. June, 1919.— Double female flowers of Begonia, a monoecious 

 plant with terminal male and lateral female flowers, pollinated by strain with only single flow- 

 ers gave single generally dominant but segregation irregular and not clearly understood. 

 Transitional forms appeared. An average of 1 double in 32 was obtained but many large fam- 

 ilies were without doubles and the figures are thought to have no general significance. Back 

 crosses were also irregular. Authors noted that while doubleness is distributed genetically 

 according to strict allclomorphic rules in other plants great irregularity prevails in Begonia. 

 A pure-breeding single-flowered Begonia Davisii from Peru crossed on common doubles 

 gave only double-flowered offspring contrary to usual behavior. Total of 405 plants grown 

 with only 18 having less than complete doubling. Novel conclusion is reached that this pure 

 single-flowered form is genetically all double on male side. Crosses between this Peruvian 

 species and a horticultural type, B. Lloydii, having double male flowers which produce pol- 

 len, gave no clear indication of linkage of doubleness with sex except in the case of one Fi plant. 

 This individual self-fertilized gave only two plants, both singles. Pollinated by the single 

 Davisii it gave 11 singles, and by the double Lloydii 5 singles and 1 slightly petalodic. Used 

 as pollen parent it gave with Lloydii 27 doubles, 14 half doubles and 5 slightly petalodic. 

 Hence the ovules at least were predominantly single-bearing. Sex linkage in Petunia, Mat- 

 thiola, Campanula and Oenothera is also discussed. — D. F. Jones. 



2082. Baur, Erwin. liber Selbststerilitat und iiber Kreuzungsversuche einer selbst- 

 fertilen und einer selbststerilen Art in der Gattung Antirrhinum. [On self-fertility and cross- 

 ing experiments with a self-fertile and self-sterile species of Antirrhinum.] Zeitschr. indukt. 

 Abstamm. Vererb. 21: 48-52. May, 1919. — The several species of Antirrhinum investigated 

 varied in regard to self-sterility. A . siculum and A . ma jus were perfectly self-sterile. While 

 A. latifolium and ,4. tortuosum, except for the occasional setting of seed late in the season, 

 were sterile with their own pollen during their first year, they were self-fertile the next. An 

 undetermined variety of the latter was self-sterile in the first generation but self-fertile in 

 succeeding generations. A. Ibanyezii, A. molle, A. glutinosum, and A. hispanicum were self- 

 sterile. — Hybrids between self-sterile species were all self-sterile. In hybrids between self- 

 fertile and self-sterile species self-fertility is dominant, a 15 : 1 ratio resulting in F t . — E. S. 

 Anderson. 



2083. Bayla, A. M. Hybridization of eggplants. Philippine Agric. 7: 66-71. 1918.— 

 Shows possibility of crossing native on foreign varieties, giving increased vigor in the hybrid. 

 The hybrid is quite resistant to bacterial disease, but this character was lessened in the sec- 

 ond generation. Commercial possibilities of the work are noted. — C. E. Myers. 



2084. Becking, L. G. M. Baas. Over getallenverhoudingen in panmictische populaties. 

 [Numerical conditions in panmixial populations.] Nederland. Kruidkundig Arch. 1918: 61-69. 

 May, 1919. — Genetic formulae are given or suggested for the Mendelian principles as applied 

 to factors of human population. There is a discussion of the various formulae applied by 

 previous writers with criticisms and the opinion of the author tends towards an expectation 

 of results pointing to equilibrium of factors as inferred by deduction.—/. A. Nieuwland. 



2085. Becking, L. G. M. Baas. Some numerical proportions in pan-mictic populations. 

 RecueilTrav. Bot.Nderland. 15:337-366. 1 pi. 1918. Panmictic populations are those in which 

 mating between the different genotypes is free and unrestricted. Hardy showed that with one 

 factorial difference a constant limit is reached in F 2 . With more numerous factors the limit 

 is reached only after numerous generations. Formulae are derived for these cases and it is 



