244 EXPERIMENT STATION RECORD. [Vol. 40 



soils either rich or poor in limp were aboul an average of the yields secured 

 from the lowe highest rates of seeding. 



On the basis of the increase In the yield of dry matter the use of hairy 

 vetch in the seed mixtures was found profitable and the culture of this crop to a 

 greater extent, especially in regions whore droughts are likely to occur in 

 spring and early summer, Is recommend 



The mechanical factors determining the shape of the wheat kernel, S. 

 Boshnakian (Jour. A»icr. s<,<: i 10 {1918), No. o. pp. 205-209, fig. 1). — 

 Factors affecting the shape of the wheat kernel are briefly discussed, the Shape 

 and stiffness of the glumes being deemed the principal mechanical influence 

 involved, Other factors of a mechanical nature receiving consideration in- 

 clude the size and sha] f the space In which the grain develops, the number 



of grains in the spikelet ami their position, the density of the head, and the 

 pressure caused by the growth of different parts of the head Purely genetic 

 factors are said to be responsible for the production of certain grain forms, :t s 

 Illustrated by the shortness of the grain of the dub wheats, the unusual lengtb 

 of Polish \\ beats, etc. 



The effect of sodium nitrate applied at different stages of growth on yield, 

 composition, and quality of wheat. II, .1. DAVIDSON and J. A. LaClXBC [JOWT. 

 Ainrr. Boo. Aoron., 10 (V.'l- ". j,p. 19$-198).~\:\ continuation of work 



previously OOted (B. S. l: . 38, p. 438), the authors present and discuss ad- 

 ditional data to show the effect ef various a i ipl iea t i«.n< of nitrate of soda upon 

 the ash, potash, ami phosphoric acid content of the wheat grain and upon the 

 nitrogen content of the straw. Experimental work coi I In Nebraska dur- 



ing ion is said to have corroborated fully the previous observations with 

 respect to the specific effeel of nitrogen at the different - of growth and 



with regard to the advisability of laying out ti after the crop is up. 



No distinct effeel of the different treatments npon the ash. phosphoric add 

 or potash contenl of the grain was noted. The protein of the straw, 



however, showed the same general tendon. iin. Increasing 



with nitrate applications at the Becond Btage of growth. I • s of 



straw as well as of grain followed the application of nitrates :t t the first Stage, 



Potasdum chlorld seemed to depress the protein content of the straw. 



The wheat problem, W. Cbookzs i V rk aui London: Longman*, Green, 

 d Co., t917, S. "1-. rev. and > »!.. />/<. .Y17 + /00. figs, t; ui**. in Nature [London], 

 100 (1918), No. 8518, pp. ',-'-'. PW).— This is a third and revised edition of a 

 previous work, with an introduction by Lord Rhondda, an additional chapter 

 by the author on Recent Devdopments <>f the Wheal Problem, bringing the sta 

 tistical information up to date, and a chapter by R. H. ROW on Future Wheat 

 Supplies. The author's thesis, briefly stated. Is that since a large and pro- 

 gressively Increasing proportion of the world's Inhabitants Peed upon wheat the 

 time will arrive when the world's wheat production will not meet the demand 

 and famine must follow. The possibility of Increasing the ge planted 



to wheat is shewn to be approaching Quality, m sdtatlng an Increased yield 



per acre which he maintains can be mosl readily achieved by the Increai 



use of nitrogenous fertlll era Maintaining further that the world's demands 



for these fertilizers would rapidly exhaust all existing Supplies (sulphate of 

 ammonia, nitrate of BOda, and guano), the fixation of atmospheric nitrogen by 

 chemical processes Is deemed to be the only practicable solution of the problem. 



The chapter i>.\ 1:. 11. Rew, based on more recent and detailed statistics, in- 

 dicates the possibilities of extending the world's wheat supply without cheap 

 nitrogenous ferl llizera 



Yautia and gabi tests. R, A. \i,u>'M\ [Philippine Igr. and Port 



(/.''/: 1. \o. 2-8, pp. '/■> 1 /• rieici teats of different planting methods, of 



