No. 4, January, 1921] GENETICS 255 



1735. Philips, A. G. Preferential mating of fowls. Jour. Amor. Assoc. Instr. and 

 Invest. Poultry Husb. 5:28, 30-32. 6 fig. 1919.— Continuous observations were made on 

 several flocks, each consisting of one male and 10-28 females. The number of matings per 

 hen per day ranged from 0-5 and was controlled by her. Under some circumstances a single 

 male mated more than 40 times in one day. — //. D. Goodale. 



17.5G. Poll, Hbinkich. Mischlingsstudien VIII. Pfaumischlinge, nebst einem Beitrag 

 zur Kern-Erbtrager-Lehre. [Hybridization studies VIII. Peafowl hybrids and a comment 

 on the theory of nuclear bearers of heredity.] Arch. Mikros. Anat. 94: 365-458. 5 fig. 1920. 



1737. Quaglini, Luigi. Cruzamiento y fecundacion artificial de la cafia de aziicar. 

 [Cross fertilizing sugar cane.] Revist. Agric. Com. y Trab. 3: 44-46. 1 fig. 1920. 



1738. Rasmuson, Hans. Uber einige genetische Versuche mit Papaver Rhoeas and 

 Papaver laevigatum. [Some genetical experiments with Papaver Rhoeas and Papaver laevigatum. 

 Hereditas 1: 107-114. 1920.— By crossing a Rhoeas-form having divergent hairs at the pe- 

 duncle with another one having appressed hairs, a segregation in proportion 1 : 1 takes place 

 in Fi. The divergent hairs might be dominant, to judge from the species hybrid Rhoeas X 

 dubium. Yellow latex dominates over white. The segregation in Fj ismonohybrid. Green 

 color of leaves dominates over yellow-green. The segregation in F2 is monohybrid. A gene, 

 S, produces a black base-spot on the petals; another, W, produces a white spot; S is epistatic 

 to W. If both genes are missing the sepals will be unspotted. W affects also the flower color, 

 or is linked with a gene that affects the color. — K, V. Ossian Dahlgren. 



1739. Rasmusson, J. Mendelnde Chlorophyllfaktoren bei Allium cepa. [Mendelian 

 chlorophyll-factors in Allium cepa.] Hereditas 1: 128-134. 1920.— After self-fertilization of 

 a number of flowers of different commercial sorts in several pedigrees, light green, yellow, and 

 white plants were to be found, in relative number which rather well agreed with the Mendelian 

 ones. This is demonstrated by several tables. The complete production of chlorophyll 

 depends on a suite of factors, of which one factor will take effect only if all previous factors in 

 the suite are present. At two points of the suite homomeric factors are acting. — K. V. Ossian 

 Dahlgren. 



1740. Raum, J. Ein weiterer Versuch fiber die Vererbung der Samenfarbe bei Rotklee. 

 [A further study concerning inheritance of seed color in red clover.] Zeitschr. Pflanzenziicht. 

 7: 149-155. 1920. — Both violet and yellow are generally found on individual seeds of red 

 clover (Trifolium pratense), but occasionally seeds are either wholly violet or yellow. Colors 

 are found in various degrees of saturation. Satisfactory Mendelian explanation would 

 involve theory of multiple factors. Technique necessary for critical study would be very 

 difficult because of flower size and almost invariable and necessary habit of cross-fertilization. 

 Solution of problem is of less economic importance than many others not yet worked out in 

 red clover. Seeds of known color were selected from individual unguarded plants and planted. 

 Seeds from 36 daughter plants derived from 11 mother plants were compared with mother- 

 plant seeds. Author states that daughter seeds were similar to mother-plant seeds, but had 

 a tendency toward increased amount of yellow. Author does not believe, as some suppose, 

 that seed color is correlated with earliness. — L. R. Waldron. 



1741. Raum, S. Beitrage zur Praxis der Grassamenerzeugung und des Grassamenbaues. 

 [Contributions to the practice of grass-seed production and grass-seed culture.] Illustr. 

 Landwirtsch. Zeit. 1920: 25-26. 1920. — Some results have already been secured in breeding 

 of grasses at Weihenstephan. Two forms of florin grass differing in times of development were 

 obtained. In meadow panicle, narrow- and broad-leaved forms occurred in population. 

 A series of types was isolated in meadow foxtail grass. In red fescue-grass a form occurred 

 well supplied with runners, and a similar thing was seen in meadow fescue. Golden oats of 

 Bohemian and Tyrolian origin revealed few differences. In French ray-grass, only minute 

 differences were observable, and hereditary maintenance of these was difficult. A similar 



