258 GENETICS [BoT. Abbts., Vol. X, 



and those reported as occurring in the wild, or represented by specimens in various museums. 

 White spotting, albinism, yellow, black, and the pink-eyed colored variation are found to 

 be rather widely distributed mutations from the agouti color, typical of wild rodents. Com- 

 munity of genes, which seems probable in many cases, has been proved by similarity in linkage 

 relations in the case of the pink-eyed colored variation and albinism in rats and mice. — 

 Sewall Wright. 



1700. Ettler, K. Ein bemerkenswerter Fall von Knollenfarbabanderung der Kartoflfel. 

 [A remarkable case of change of color in potato tubers.] Deutsch. Landw. Presse 1919: 161- 

 162. 1919. — This is an account of a single plant (grown from a white tuber) which gave 10 red 

 tubers and 1 tuber red at stem end and white at crown end. The tuber producing this plant 

 was the only one from a plant whose aerial parts were killed by cold, and the variation is 

 therefore supposed to have been induced by frost. [From anonymous review in Zeitschr. 

 Pflanzenzucht. 7: 35. 1919.]— J. P. Kelly. 



1701. Eyster, Lewis A. Heritable characters of maize. VII. Male sterile. Jour. 

 Heredity 12: 13S-141. Fig. 21-23. 1921. — A description and a photograph of the male- 

 sterile character in maize, together with some genetic data on its inheritance, are presented. 

 Defective anthers in which no pollen is produced are borne on an otherwise normal plant. 

 Data from 2 heterozygous, self-pollinated ears and 3 back-crosses show that male-sterile is 

 inherited as a simple Mendelian recessive to the normal type of tassel. — E. W . Lindstrom. 



1702. Eyster, William H. Heritable characters of maize. VT. Zigzag culms. Jour, 

 Heredity 11: 349-357. Fig. 8-16. 1920. — The zigzag culm described was first noted by 

 R. A. Emerson in F4 cultures of a cross between Tom Thumb and a Missouri dent corn. Emer- 

 son found that plants selfed bred true for this character and, when crossed with normal plants, 

 produced apparently normal Fi plants. The zigzag culm appears about the time of tassel 

 emergence, the 1st indication being an apparent flattening and broadening of the culm in 

 the ear-shoot region caused by the leaf sheaths pulling away from the culm. Extracted 

 recessives from crosses vary considerably in the expression of this character. F2 progenies 

 of outcrosses with normal plants in segregating deviate but slightly from the 15 : 1 ratio ex- 

 pected when 2 duplicate factors are involved in the expression of a character. Results of 

 back-crosses of Fi plants with the zigzag parental type indicate that zigzag culm is expressed 

 only when at least 2 factors are recessive. — H. M. Steece. 



1703. Freckmann, W. Ein Beitrag zur Frage der Futterpflanzenzuchtung. [A contri- 

 bution to the question of forage-plant breeding.] Mitteil. Deutsch. Landw. Ges. 36: 550-553. 

 4 fig. 1921. — A brief account is given of some work done at Moorland experiment station, 

 Neuhammerstein, with Poa pratensis, timothy, and tall meadow oat grass. The author con- 

 siders that of the 3 methods used at the station, namely, general improvement, group selection, 

 and individual selection, group selection gives the most rapid results for practical work. 

 Pasture and meadow forms of Poa pratensis have been isolated, and some variations in the 

 structure of the panicle are described. A table of analyses is given to show that strains of 

 timothy having higher protein content can be developed. A tall, sturdy, late-maturing oat- 

 grass, obtained by selection, is illustrated. — A. J. Pieters. 



1704. Gassner, G. Untersuchungen iiber die Sortenempfanglichkeit von Getreidepflanzen 

 gegen Rostpilze. [Studies on the susceptibility of cereal varieties to rust.] Zentralbl. Bakt. 

 II Abt. 49: 7-9, 185-243. 1919. — In studying the reaction of various cereals to Puccinia 

 graminis, P. triticina, P. coronifera, and P. Maydis, 8 grades of rust attack were distinguished; 

 stages of development of the hosts from young seedlings to mature plants were likewise recog- 

 nized. Observations were made in Uruguay (1907-10) on pure lines of small grains obtained 

 from Germany and in South America. In both barley and wheat the stage of development of 

 the host is particularly important in its reaction to P. graminis. To P. graminis barley 

 varieties showed no true resistance; a German variety of oats, Beseler II, was very resistant, 

 while a Uruguay variety proved susceptible; other European oats, among them Svalof's 



