No. 1, July, 1920] GENETICS 85 



prc-mutation period which prepares way for period of repeated mut -it inn ; latter ceases when 

 labile pangencs become stable. Author believes De Vrics has neglected action of physico- 

 chemical forces as causes of mutation; IMaringhem's work on traumatism in maize is cited as 

 confirmatory here. Considering all things mutation t beory is deemed not discredited. — ./. P. 



553. Qoultkk], J. M. Aaron Aaronsohn. Bot. Olaz. 68 : 388-389. 1 portrait. Xov., 

 1919. — Subject of this brief sketch lost his life May 15, 1919 in an airplane accident in Prance. 

 He is well known for his discovery of wild wheat in Palestine, whose value as a foundation for 

 the production of varieties suited to arid regions, he immediately recognized. He organized 

 the Jewish Agricultural Experiment Station at Haifa, Palestine, where breeding of cereals 

 and fruits was undertaken. "In Aaronsohn's death, at the age of 42, the science of plant- 

 breeding, especially in its practical application in semi-arid regions has probably lost its most 

 promising investigator." — Geo. H. Skull. 



554. Coulter, Merle C. Quantitative nature of sex. [Rev. of: Schaffner, John H. 

 The nature of the dioecious condition in Morus alba and Salix amygdaloides. Ohio Jour. Sci. 

 19: 409-416. 1919. (See Bot. Absts. 3, Entry 1575.)] Bot. Gaz. 68: 485. Dec, 1919. 



555. Crow, J. W. Vegetable seed growing and breeding. Proc. Amer. Soc. Hortic. Sci. 

 15:S8-93. 1918. — From work being carried on at the Agricultural college at Guelph, On- 

 tario, it is found that good seed of most vegetable crops can be grown in Canada. As most 

 varieties of vegetables are far from pure author recommends that growers select their own 

 seed with aim of securing greater uniformity. He gives suggestions on methods of selection, 

 and details of drying and curing seed. — John Bushnell. 



556. Cutler, G. H. A dwarf wheat. Jour. Amer. Soc. Agron. 11:76-78. 1919. — In 

 commercial plat of Marquis wheat a dwarf plant occurred. Some typical Marquis heads 

 were selected and sown in head rows. One row produced tails and dwarfs. Origin of dwarf 

 was not clear. Author concludes dwarfness is simple dominant to tallness. [See also Bot. 

 Absts. 3, Entry 171.]— H. H. Love. 



557. Dahlgren, K. V. O. Uber einige Kreuzungsversuche mit Chelidonium majus L., 

 Polemonium coeruleum L., und Lactuca muralis L. [On several crossing experiments with 

 Chelidonium majus L., Polemonium coeruleum L., and Lactuca muralis L.] Svensk. Bot. 

 Tidskr. 12: 103-110. 1918. — Chelidonium majus with normal leaf and single flower crossed 

 with C. laciniatum with laciniate leaf and double flower, results in dominance of normal leaf 

 and single flower and a 9:3:3:1 segregation in F 2 . In Polemonium coeruleum L. blue flower 

 color is dominant to white. In Lactuca muralis L. the normal green leaf was found to be domi- 

 nant to red leaf with a 3:1 segregation in F 2 . — Karl Sax. 



558. Davenport, C. B. Exhibit showing the results of selection for a new buff race. 

 Proc. Soc. Exp. Biol, and Med. 16: 124-125. 1919. — An attempt was made to create a uniform 

 buff race from the jungle fowl by crossing and selection, but at the end of 10 years no prog- 

 ress was evident. The author concludes that the original buff race of domestic poultry 

 probably originated as a xanthic sport. — H. D. Goodale. 



559. Davenport, Charles B. [Rev. of: Popenoe, Paul, and Roswell H. Johnson. 

 Applied eugenics. 14 X 20 cm., v + 459 p., Jfi fig. Macmillan Co.: New York, Oct., 1918. 

 See Bot, Absts. 3, Entry 279.] Mental Hygiene 4: 248-249. Jan., 1920. 



560. de Beauveric, J. Los methodos des eleccion aplicados a los cereales. [The methods 

 of selection applied to the cereals.] Jalisco Rural [Mexico] 1 : 213-215, 233-235, 256-25S. 1919. 

 —Popular. 



