214 GENETICS [Bot. Absts., Vol. V, 



1617. Reighard, Jacob. The breeding behavior of the suckers and minnows. I. The 

 suckers. Biol. Bull. 38: 1-32. Jan., 1920. — The white sucker (Catostomus commersionii) , 

 the red-horse (Moxostoma aureolum) , and the hogsucker (Catostomus nigricans) breed in the 

 swift water of small streams on gravel bottom. In all, the breeding males bear pearl organs, 

 and in the hogsucker the female also bears them. In spawning, those surfaces of the male 

 that are rendered rough by the pearl organs are brought into contact with the female, and 

 aid the fish in maintaining their relative positions. In the white sucker and the red-horse, 

 two males pair with the female at one time, one on either side of her. In the hogsucker, 

 six or eight males may pair with the female at one time. In each species, the female repeats 

 the spawning act in many places and with different groups of males. The male does not enter 

 into combat with other males, but cooperates with them. The relation of the sexes is thus 

 promiscuity, not polyandry or polygamy; this promiscuity is not found in fishes in which 

 combat takes place between the males. — Bertram G. Smith. 



1618. Renner, O. Zur Biologie und Morphologie der mannlichen Haplonten einiger Ono- 

 theren. [Biology and morphology of the male haplonts of some Oenotheras.] Zeitschr. Bot. 

 11:305-380. 39 fig. 1919. 



1619. Renner, O. Bemerkungen zu der Abhandlung von Hugo de Vries: Kreuzungen 

 von Oenothera Lamarckiana mut. velutina. [Comments on the paper by Hugo de Vries : Crosses 

 of Oenothera Lamarckiana mut. velutina.] Ber. Deutsch. Bot. Ges. 36: 446-456. 1918. 



1620. Richardson, A. E. V. Production of cereals for arid districts. Agricultural 

 research in Australia. Advisory Council Sci. and Ind. Commonwealth of Australia Bull. 7: 

 57-77. 1918. — Following a general discussion of location of arid regions, progress of cultural 

 methods, differences between species and their ability to withstand drought, and relation of 

 the migration ratio (i.e., ratio of grain to stalk) to drought-resistance, author describes the 

 Hays centgener-plot system of wheat breeding. Cross-breeding as a method of producing 

 new types is considered with brief summary of Mendel's principles. In this connection a 

 list of dominant and recessive characters in wheat and barley is given. — Attempt was made to 

 determine whether high and low yielding power are Mendelian characters. A high-yielding 

 variety of wheat such as Federation or Yandilla King was crossed with one of low yield such 

 as Huguenot. In the F2 the plants were grown in centgener plots and each plant harvested 

 separately. While the parental varieties give normal frequency curves the F 2 appears to show 

 segregation into two distinct groups, one consisting of high yielding plants (several of 

 which outyield the best parent) and one of low yielding plants. Progenies of both groups 

 were grown and the results indicate that the observed differences were inherited. — By propa- 

 gating the extreme plants found in F 2 of a cross between a two-rowed bearded and a six-rowed 

 skinless variety of barley a new race has been obtained which is six-rowed and bearded and 

 exceeds the parents in migration-ratio as well as in yield. — J. H. Kempton. 



1621. Roberts, Herbert F. The founders of the art of breeding. Jour. Heredity 10: 

 99-106. 4 fig. Mar., 1919. Ibid. 10: 147-152. 1 fig. Apr., 1919. Ibid. 10: 229-239. 1 fig. 

 May, 1919. Ibid. 10: 257-270. June, 1919.— See also Bot. Absts. 5, Entry 90. 



1622. Rolfe, R. A. The pre-Mendelian age. Gard. Chron. 66: 288. Dec. 6, 1919 — 

 Author takes somewhat positive attitude regarding Mendel and the supposed sanctification 

 of his results, basing his objections upon the fact that Goss, Seton, Knight and Gartner all 

 experimented with peas, obtaining concurrent results as to the uniformity in the Fi, and diver- 

 sity in the F 2 generations, the overlooking of which data by Mendel and his commentators, 

 seems to the author curious, and a manifest fault subject to criticism. Author thinks that 

 Mendel has blinded all investigators to the merits of those who preceded him. — H. F. Roberts. 



1623. Romell, Lars-Gunnar. Nagot om artbildningsproblem. [On problems of the ori- 

 gin of species.] Skogsvardsforeningens Tidskr. 18: 92-100. 1920. — After brief description of 

 different theories concerning origin of species author discusses rather particularly the treatise 



