FIELD CROPS. 631 



erations which bred true for leaf number, ^riving no greater variation than 

 the parents, 2 were intermediates. 



"These results give further confirmation of the hypothesis that the inheri- 

 tance of quantitative characters, such as size, shape, and number of various 

 plant organs may be due to the interaction of a multiplicity of factors, each in- 

 herited separately and capable of adding to the character, the heterozygous 

 condition being half the homozygous. The difficulty of determining the num- 

 ber of factors involved is very great, owing to the obscuring effect of fluctuat- 

 ing variability." 



A bibliography is appended. 



The origin of Triticum monococcum, A. Schulz (Ztschr. Qesam. Oetreidew., 

 4 {lfU2), Xo. 11, 1)1). JOr-JO.'O .—Continuing earlier work (E. S. R., 26, p. 827), 

 this article briefly discusses the appearance of 2 subspecies of this plant, one 

 in Euroi>e and the other in Asia. 



A Rieti hybrid of wheat, Schribaux (Bui. Soc. Nat. Agr. France, 72 (1912), 

 No. 7, pp. 636-640). — A method of producing a hybrid by crossing the Rieti and 

 Japhet varieties of wheat is described. The hybrid proved to be very pre- 

 cocious, awnless, and adapted to the southeastern part of France. 



Farmers' experiment plats, H. Ross et al. (.If/r. Oaz. N. S. IFaZes, 2^ (1913), 

 No. 4> PP- 277-294)- — In continuation of work already noted (E. S. R., 27, p. 

 840), this reiK)rt gives the results of farmers' wheat experiments. Including 

 variety, manurial, and cultural tests in 4 different districts. 



Some experiments and observations on the control of [germination of] 

 seeds, H. Pieper (Fiihlinff's Landtv. Ztg., 62 (1913), No. 10, pp. 361-367).— In 

 experiments on the influence of light on the germination of Poa pratensis and 

 Apera spica venti, exposure to the light during the whole of 7 days gave a 

 higher percentage than any less number of days of light, or than darkness dur- 

 ing the entire period. Hulled seed germinated better in both light and dark- 

 ness than did unhulled seed. With Loliuin weHterwohHcum there was little 

 difference in the germination between seeds that had been swollen in light for 

 24 hours and those germinated in both light and darkness. With seeds of P. 

 pratcnsis those rubbed out of the panicle germinated better in the darkness 

 than those either pulled out or left intact, while in the light there was prac- 

 tically no difference in the 3 conditions. Both L. italicum and L. westerwoldi- 

 cum germinated better on blotting paper in light than in darkness. Barley 

 and spring wheat germinated better in a temperature of from 10 to 12° C. 

 than at 20°. 



Wild oats, E. Rabat^ (Prog. Agr. et Tit. (Ed. VEst-Centre), 34 (1913), 

 No. 32, pp. 166-180, figs. 5). — In a study to determine methods of eradication of 

 this weed and hybrids with cultivated varieties, the author reached the fol- 

 lowing conclusions : Severe winters tend to decrease its appearance. Deep 

 plowing, with thorough surface cultivation, does much to destroy it during 

 the present season, but favors its appearance in succeeding cereal crops. It 

 Is not advisable to sow oats, wheat, or clover on soils that are known to be 

 badly infested with wild oats, but cultivated crops should be planted for at 

 least 2 years, with clean cultivation. 



Other less effective methods of combating the weed were hand hoeing, plant- 

 ing in drills to allow of spraying with a 10 per cent solution of sulphuric acid, 

 pulling In April or May, removing the panicles early in June, cutting the crop 

 green, destroying the chaff from the threshed grain, and burning the stubble. 



The influence of corn flower (Centaurea cyanus) on the harvest of winter 

 rye and barley, A. Chrebtow (Trudy Biuro PrlkJ. Bot. {Bui. Angeic. Bot.), 

 6 (1913), No 5, pp. 344-S4S)' — In this experiment the plats were sown to vary- 



