252 GENETICS [Box. Absts., Vol. VII, 



Relationship Coefficient in areas, using the actual percentage of the maximum area as meas- 

 ure. The new Total Relationship-Inbreeding-Index finally measures — -also in areas — 'the 

 proportion of the total inbreeding in the pedigree of an individual that is due to the relation- 

 ship between its parents. The full system of measurements is used as an example on the 

 pedigree of the Jersey bull King Melia Rioter 14th. — -Tage Ellinger. 



1745. Emerson, R. A. Heritable characters of maize. II. Pistillate-flowered maize 

 plants. Jour. Heredity 11:65-76. 8 fig. Feb., 1920.— Description and genetic behavior of 

 two types of terminal inflorescence of maize to which the names "tassel seed" and "tassel 

 ear" have been given. The two types are genetically distinct but further work must be done 

 to determine the exact factoral and linkage relationships. [See also Bot. Absts. 7, Entry 

 1684.]—/. H. Beaumont. 



1746. Ernst, A. tJber Parthenogenesis und Apogamie. [On parthenogenesis and apog- 

 amy.] Verhandl. Schweiz. Naturf. Ges. 1919: 1-20. 1919.— See Bot. Absts. 7, Entry 1685. 



1747. Fairchild, David. Twins. Their importance as furnishing evidence of the lim- 

 itations of environment. Jour. Heredity 10: 387-396. Frontispiece, fig. 1-7. 1919.— A brief 

 philosophical discussion of the value of studies of individuals having identical germ-plasm 

 to determine the importance and limitations of environment as affecting heredity. The 

 author mentions certain of the factors of environment which do not affect hereditj'' but indi- 

 cates the significance of the work undertaken by the American Genetics Association in the 

 study of photographs and answers to questionnaires submitted by 600 twins. — J. H. Beaumont. 



1748. Feenstra-Sluiter, C. Waarnemingen en Beschouwingen over Bloei Bevruchting 

 en Zaadvorming bij Cinchona Ledgeriana Moens. [Observations and considerations of flower- 

 ing, fertilization and seed formation in Cinchona Ledgeriana Moens.] Mededeel. Kina-Proef- 



sta. 6. 35 p, 20 fig. 1919.— See Bot. Absts. 7, Entry 1686. 



1749. Firbas, Heinrich. Uber die Erzeugung von Weizen-Roggenbastardierungen. 

 [The production of wheat-rye hybrids.] Zeitschr. Pflanzenziicht. 7: 249-282. Nov., 1920. 



1750. Fischer, H. Kohlensaure und Pfianzenziichtung. [Carbon dioxid and plant 

 breeding.] Zeitschr. Pflanzenziicht. 7: 364-366. Nov., 1920. 



1751. Fischer, H. Orthogenesis, Mutation, Auslese. [Orthogenesis, mutation, selec- 

 tion.] Naturw. Wochenschr. 19:561-566. 1920. 



1752. Fleischer, B. tJber myotonische Dystrophie mit Katarakt. [On myotonic dys- 

 trophy with cataract.] Arch. Ophthalmol. 96: 1-43. 1918.— See Bot. Absts. 7, Entry 1803.] 



1753. Fleischer, Bruno, und William Josenhans. Ein Beitrag zur Frage der Verer- 

 bung der familiaren Sehnervenatrophie (Leberscher Krankheit). [Contribution to the question 

 of the inheritance of familial atrophy of the optic nerve (Leber's disease).] Arch. Rass. Gesell- 

 schaftsbiol. 13: 129-158. 5 pi. 1920. 



1754. France, R. H. Der Parasitismus als schopferisches Prinzip. [Parasitism as a 

 creative principle.] Centralbl. Bakt. 59: 54-64. 6 fig. 1920.— See Bot. Absts. 7, Entry 1799. 



1755. Frimmel, Fr. tJber einem Versuch der Ziichtung schwarzer Farbentone an der 

 Gartenprimel. (On an attempt to breed black color-tone in the garden Primula.) Zeitschr. 

 Pflanzenziicht. 7:346-356. Nov., 1920. 



1756. Gates, R. R. Mutational v. recapitulatory characters. Rept. British Assoc. Adv. 

 Sci. Bournemouth Meeting 1919 : 340. 1920.— Characters are divided into two classes : Muta- 

 tions which owe their origin to a nuclear change and modify every stage of the ontogeny, 

 and recapitulatory characters which arise through the impress of environment and usually 

 involve adaptation to new conditions. 



