44 



in the cortical tissues, and the bacteria do not swell out to form 

 the so-called " bacteroids." In plants grown without boron, 

 the number of nodules that attain macroscopic size is much 

 reduced. When weakly developed strands enter the nodule, the 

 amount of tissue containing bacteroids is closely correlated with 

 the extent of the strands. 



In the plants bearing these abnormal nodules the quantity 

 of nitrogen fixed per nodule is small, being, in one experiment, 

 less than one-tenth of that fixed in normal plants. The defective 

 vascular supply is thus accompanied, on the one hand, by a 

 reduced development of " bacteroid " forms and, on the other 

 hand, by reduced nitrogen fixation. 



In the absence or weak development of vascular strands in 

 the nodule, the bacteria tend to become parasitic, attacking the 

 protoplasm of the host cell. This attack is chiefly directed 

 towards the more densely protoplasmic cells of the nodule. It 

 is suggested that this change in the relations between the micro- 

 organism and its host is connected with the loss or reduced 

 supply of the carbohydrate energy material normally brought 

 into the nodule by the vascular strands, the bacteria thus being 

 reduced to making use of the protoplasm of the host as a source 

 of energy. 



IV. E. J. Russell. Journal of the Institute of Brewing. 



A full account of the work discussed on p. 17 of this 

 report. 



V. H. Lloyd Hind. " Report on the Analyses of the 



Barleys of 1922 and of the Malts made from them. 1 ' 

 Journal of the Institute of Brewing, 1924. Vol. 

 XXX., pp. 969-986. 



This report gives the results of the analyses of the barleys 

 grown under the auspices of the Institute of Brewing Barley 

 Research Scheme in 1922, together with those of the malts made 

 from them. 



The first season's determinations were necessarily of an 

 exploratory character, quality being a very elusive property which 

 has not yet been reduced to exact chemical terms. The relation- 

 ships between the total nitrogen and the other quantities generally 

 estimated in malt analyses have been studied. The usual 

 physical valuation of barley, good as it often is in the hands of 

 experts, is shown to fail in certain conditions, some of the low 

 valued barleys giving quite useful malts. The influence of 

 regional conditions, soil, season, etc., on the composition of the 

 barley and malts is shown to be greater than that of the different 

 manurial treatments at each centre. 



(b) Statistical Methods and Results. 



AGREEMENT OF THEORY AND OBSERVATION. 



VI. R. A. Fisher. " Statistical Tests of Agreement between 



Observation and Hypothesis." Economica, 1923. Vol. 

 III., No. 8, pp. 139-147. 

 In .ill quantitative work, both in biology and in agriculture, 

 tests oi agreemenl between observation and hypothesis assume 



