4 io SCIENCE PROGRESS 



any consideration of environmental or internal factors. " The 

 most interesting thing about this Law of the Minimum," says 

 Prof. Hooker, " is not how it works, but when it does not work." 

 There is a fundamental discrepancy between the Law of the 

 Minimum and Galton's Law of Averages. In every case where 

 Galton's law holds the Law of the Minimum does not hold. The 

 resultant size or weight of an organism shows that these are 

 not determined by the limiting factor of its environment. The 

 factors giving the largest values are utilised to some extent 

 to alleviate the influence of the limiting factors. Compensa- 

 tion or integration takes place. Prof. Hooker then outlines 

 very briefly the results and outlook to be obtained from a 

 realisation of this principle of integration. Response to 

 stimuli, development, evolution, and bio f ic succession are the 

 main integrating causes which will have to be considered in 

 facing the physiological problems of the living plant, — its growth, 

 maturation and general metabolism. When individual races 

 and associations are concerned the limiting factor becomes 

 merely the stimulus to which the whole system responds. 

 The final result always approximates to an average of all the 

 resources at disposal. 



The Next Step in the Improvement of Wheat Cropping, by 

 Prof. H. L. Bolley (Science, vol. xlvi. July 20, 191 7). — We 

 meet again here with the same demand for plant physiological 

 organisation and development ; and in this case in direct 

 connection with its value as an applied science. The demand 

 made, which, if carried into effect, Prof. Bolley considers would 

 have such striking and beneficial results as to gain the immediate 

 support of the agricultural community, is no less than that a 

 large and trained body of physiologists should be put on a 

 field-crop survey to locate seed of the highest weight and colour 

 quality, free from disease and weather effects, and to locate also 

 the various soils upon which such seed should be sown . Further, 

 it would be necessary to see that the seed is procured and sown 

 in suitable soils, and that the necessary disinfection of the 

 seed is carried out. 



The John Hopkins University Circular, 191 7. — In this 

 circular, under the head of " Contributions to Plant Physiology," 

 from the Department of Plant Physiology, Prof. Burton E. 

 Livingston, in an Introduction, outlines in a masterly manner 

 the aims of modern plant physiology, and touches on the 



