No. 4, January, 1921] GENETICS 241 



1652. Correns, C. Vererbungsversuche mit buntblattrigen Sippen. III. Veronica 

 gentianoides albocincta. IV. Die albomarmorata- und albopulverea-Sippen. V. Mercurialis 

 annua versicolor und xantha. [Genetical studies with variegated races. III. Veronica gen- 

 tianoides albocincta. IV. The albomarmorata and albopulverea races. V. Mercurialis annua 

 versicolor and xantha.] Sitzungsber. Preuss. Akad. Wiss. Berlin 6, 7: 212-240. Ht_'(). 



1653. Crandall, C. S. The apple cross Tolman X Malus Toringo. Proc. Amcr. Soc. 

 Hortic. Sci. 16: 60-66. (1919). 1920. — Cross between Tolman, a standard variety of apple, 

 and a dwarf form of Malus Toringo gave Fi seedlings intermediate for characters studied, 

 but more nearly approaching dwarf parent.— Sec also Bot. Absts. 6, Entry 1148. — Fred 

 Griffee. 



1654. Czuber. Die Anwendung der Wahrscheiniichkeitsrechnung auf Fragen der Land- 

 wirtschaft. [The application of probability calculations to agricultural questions.] Zeitschr. 

 Landw. Versuch. Osterreich. 1918: 1-100. 1918. 



1655. Danforth, C. H. Observations on brachydactylism in the fowl. Anat. Rec. 14: 

 33-34. 1918. — Author's abstract of paper presented at the Thirty-fourth session of the 

 American Association of Anatomists, Dec. 29, 1917. — A form of brachydactylism affecting 

 particularly the fourth digit is of common occurrence in the fowl. It is usually associated with 

 booting (feathered tarsi). The extent to which the fourth toe is shortened ranges from a 

 condition in which all five phalanges are present, but with a total length slightly less than 

 normal, to a condition in which the toe is greatly shortened and the number of phalanges 

 reduced to two. The fourth phalanx is the first to be affected, followed by the third, and 

 then by the fifth. The skeletal elements seem to disappear through a process of coalescence 

 rather than one of suppression. — Examination of developmental stages show that the brachy- 

 dactyl digits are already noticeably shortened at a time when the cartilaginous anlagen of the 

 phalanges are still in a rudimentary condition, which suggests that the brachydactylism is 

 due not to a defect inherent in the skeletal system, but more probably to an influence that 

 acts on the toe as a whole. The possibility of booting as a causative factor seems to be 

 definitely eliminated by the fact that brachydactylism may be clearly apparent before the first 

 feather germs appear on the tarsi. It seems probable that both conditions are induced by 

 some common cause, which is effective from the eighth to the tenth day of incubation. — 

 Breeding records indicate that brachydactylism is transmitted in about the same proportions 

 as polydactylism and booting. With the latter it shows a close correlation; with the former, 

 none. — C. H. Danforth. 



1656. Daniel, Lucien. Sur la stabilite et l'heredite de Crataegomespilus et des Pirocy- 

 donia. [On the stability and heredity of Crataegomespilus and of Pirocydonia.] Compt. 

 Rend. Acad. Sci. Paris 169:513-515. 1919. 



1657. Davenport, C. B. Department of Experimental Evolution. Carnegie Inst. Wash- 

 ington Year Book 18 (1919) : 123-152. 1920.— Director reports that during 1919 scientific 

 work of the Station emerged from quiescence imposed by the war. C. W. Metz, working 

 with Drosophila virilis, D. obscura and D. willistoni, discovered 23 new mutant characters 

 from March to July. E. C. MacDowell reports no new experimental facts on effects of alco- 

 hol on rats, but presents further surveys of data previously collected. One such survey 

 points to mental inferiority of rats descended from alcoholized grandparents as compared 

 with controls from normal ancestors. Cytological studies (by E. Allen) on testes of con- 

 trol and alcoholized rats revealed degeneration in both, but much more in alcoholized rats. 

 A biometrical treatment by MacDowell on data already reported on selection for bristle 

 number during 54 generations of Drosophila confirmed previous conclusions that no selection 

 effect was perceptible after first few generations. Compilation by A. M. Banta of data on 

 selection for speed of light reaction in daphnids showed no effective selection except in one 

 line. E. H. Behre found that stale sperm in pigeons does not affect sex-ratio. Banta con- 

 tinued observations on sex-intergrading daphnids along two lines: (1) detailed study of 



BOTANICAL ABSTRACTS, VOL. VI, NO. 4 



