No. 1, July, 1920] GENETICS 91 



to three years old. — (4) Breeding experiments: Full report of these experiments published in 

 Bull. 272, Maine Agr. Exp. Sta. — (5) Inheritance of twinning and problems connected there- 

 with: Observations on a free martin Led to following conclu ion : Free martin can come in 

 heat; heal can appear in cattle baving gonads very differenl in appearance from tho.se of 



either normal sex; and growth or release of egg is not cause of heat. -(6) Codperal 

 breeding records: Out of 2.~>7:\ births, 21 were twins. Combining data concerning sex with 

 data of Lillie, the ratio is 22 pairs where both are males to .'is pairs of one male and one f'-male 

 to 15 with both females, thus approaching closely a 1:2: 1 ratio. — E. Robert . 



587. GRABNER, E. Ausleseverfahren zur Massenauslese der Maiskolben. [Selection ex- 

 periences in the mass-selection of maize ears.] Zeitschr. Pflanzenziicht. 7: « > I — * '»:^ . / fig. 

 June, 1919. — A method of sorting maize ears for seed into grades according to total weight of 



ear and per cent weight of grain in total weight of ear. Ears having above 89 per cent grain 

 are divided intoG classes according to total weight of ear, ranging from 200 to 500 grams. Spec- 

 imens weighing above 450 grams and having a per cent of grain higher than SO arc put in first 

 grade. Table shows per cent of grain for ears of any given total weight, from 200 to 500 grams, 

 and weight of cob. Several years' selection in this way raised grain percentage from 65 to 

 in common maize to 82 to 83 which is figured to give an increase of 15 to 19 per cent in pro- 

 duction of grain. — D. F. Jones. 



588. Haecker, V. Die entwicklungsgeschichtliche Vererbungsregel in der Volkerkunde. 

 [The ontogenetic law of heredity in anthropology.] Zeitschr. indukt. Abstamm. Vererb. 19: 

 73-78. 191S. — Two types of heredity manifest themselves following a cross between distinct 

 races of men. With some traits segregation occurs, with others it does not. The traits that 

 segregate are believed to be the ones which owe their character to a simple causal factor and 

 which have a high degree of autonomy in development. Those that do not segregate but 

 form permanent blends are the traits of a more complicated genesis and of a low- degree of 

 autonomy. Most features of the head and face are due to multiple ontogenetic reactions 

 since the determining elements of soft tissues and bone are subject during development to the 

 interplay of complex pressures and tensions exerted by other parts. In southeastern Europe 

 the original Mongolian characteristics of Magyar and Turk have been diluted almost to the 

 point of complete obliteration in so far as most traits, — those of complex origin, — are con- 

 cerned, but at least one character, the "Mongolian spot," frequently appears in full strength. 

 The development of the latter is comparatively a simple process, merely the localized deposi- 

 tion of pigment, hence its independent segregating behavior in heredity. Similarly one may 

 explain the rather common occurrence of more or less dark-skinned people with blue eyes, 

 skin color being a complex, blending trait, eye color a simple, segregating trait. Author does 

 not commit himself as to whether blending traits, in whose development multiple ontogenetic 

 factors are involved, do or do not owe their peculiarities to multiple genes in the usual sense. 

 — C. H. Danforth. 



589. Hagiwara, T. Asagao no Ha no hutatu no Seisitu no aidano Sokwankwandkei nl 

 tuite. [On the correlation between two leaf-characters in the Japanese morning-glory.] [In 

 Japanese.] Nogakukwaiho [Report of the Agronomical Soc] 206: 897-901. Tokyo, 1919. — 

 A cross was made between a race of the Japanese morning-glory (Convolvulus) having green 

 leaves with their margins rolled upwards and another having variegated ones with ordinary flat 

 margin. Fi possesses full green leaves with ordinary flat margin. In F 2 each of these allelo- 

 morphic pairs — full greenness and variegation, flat and rolled margin — when independently 

 considered, is found to segregate respectively in typical 3 : 1 fashion ; but when both of them are 

 taken together into consideration, the ratio of the four kinds of zygotes produced, i.e., green- 

 flat, green-rolled, variegated-flat, variegated-rolled, is quite different from the usual 9:3:3: 1 

 and the author's conclusion drawn from their respective numbers — 252:26:27:69 — is that he 

 has here to do with a case of linkage of the two allelomorphic pairs above cited in the gametic 

 ratio 7: 1 : 1 : 7. — S. Ikeno. 



