1019] FIELD CROPS. 525 



distribution, the authors attempt to apply such a tost to their remits. For 

 convenience the probable error of the binomial distribution lias been calculated 

 and tables of its value for certain classes and for populations up to 500 have 

 been prepared. "It is recognized that if pure chance controls the recombina- 

 tions of factors in the combining gametes, then, in a large number of cases, the 

 differences between observed and theoretical results should be divided about 

 equally between values less than and greater than the probable error of the 

 binomial frequency distribution of those differences." 



Altogether the test has been applied to the occurrences in 1,805 different 

 cases, of which s;tt; were found to be within the probable error limits and MO 

 without. The results obtained with the different crops and with the different 

 Ifendettan ratios are regarded as quite satisfactory, and although they are not 

 deemed conclusive it is thought that "they do show that for practical purposes, 

 the Momlelian law of inheritance is an exceedingly useful tool in practical plant 

 breeding." The final settlement of the main problem is believed to await the 

 discovery by biochemists of the real mechanism of inheritance and development. 



The text is supplemented by several colored plates and photographs showing 

 the parental stock and hybrid progeny. 



On a case of permanent variation in the glume lengths of extracted 

 parental types and the inheritance of purple color in the cross Triticuni 

 polonicumXT. eloboni, A. St. C. Caporn (Jour. Genetics, 7 (1918), No. 4. PP- 

 S59-280, pis. 2. figs. }). — This paper discusses investigations initiated by Kiffen 

 in 1013 and carried forward by the author, beginning with the analysis of 

 the Fa figures. The parent strains are fully described and an accurate method 

 for measuring and tabulating glume lengths explained. In the F 2 generation a 

 marked change in the average glume length of homozygous " longs," as compared 

 with the average of the parent, T. poloninim. was observed which, under equal 

 conditions, is said to persist through int») the F 3 generation. 



A study has also been made of the purple pericarp color, including observa- 

 tions on the manner and extent of its distribution in the tissues, its develop- 

 ment and detection in minute quantities, and its inheritance with regard to the 

 latter point. A distinguishing feature is that segregations analogous to the F 2 

 segregation have not been observed in the F 3 generation. Streaking, a character 

 which appeared suddenly in the F_> generation, is said to bear some resemblance 

 to particoloring in maize, and is discussed. Cultures have been stabilized with 

 respect to color and glume length. 



Grain production and the bread situation in Switzerland, J. Wir.z {Die 

 tSetreideproduktion und! Brotversorgung der SchweUs. Zurich: Art. Inst. Orell 

 Fiissli, 1911. ,.'. <•'/.. enl., pp. lti-i. pis. 43). — This is a revised edition of a work 

 dealing in a detailed manner with the grain production and the bread situ- 

 ation of Switzerland from the Middle Ages to the present time, also with meas- 

 ures deemed essential to the maintenance and increase of domestic grain pro- 

 duction and with the regulation of the bread supplies through associations and 

 societies. 



British grasses and their employment in agriculture, S. F. Armstrong 

 (Cambridge [Eng."\: U*iv. Press, inn. pp. VI 1 1 + 199. figs. 177; rev. in Set. 

 Prop. [London], 12 (1918). No. 1,8. p. 697, 698; Physiol. AbS., 3 (1918). No. 2. p. 

 155).— This volume, designed primarily for the use of agricultural student?, 

 deals with the identification and utilization of the species of grasses found in 

 the British Isles, with special reference to those species which are most abun- 

 dant or of greatest economic importance. 



The work embraces two parts, a botanical section and an agricultural section. 

 The first section includes chapters on the morphology and biology of grasses 

 and the distribution of British grasses; artificial keys based respectively on 



