December 30, 1922] 



NA TURE 



887 



Research Items. 



Science and Philosophy. — An article by Sir 

 Oliver Lodge appears in the December number of 

 Scientia on " The Philosophy of Science or the 

 Principles of Scientific Procedure." Sir Oliver 

 endeavours to draw a clear distinction between 

 questions which definitely and legitimately belong 

 to science, and those which, though of interest 

 to science, belong to philosophv and cannot be 

 answered by the ordinary methods and procedure 

 of science. The size of an atom is an example of 

 one, the infinity of space of the other. Sir Oliver is 

 quite ready to admit that we can make no sharp separa- 

 tion between our philosophic, artistic, and scientific 

 interests, which are an integral part of human nature 

 and inextricably combined, but he seems to think 

 that on the objective plane we can separate out the 

 different realms and cleaflv demarcate their frontiers. 

 No one is likely to dispute that there are_ certain 

 kinds of fact which admit of being investigated 

 with an isolation which is practically complete. 

 What we want to know is whether any fact enjoys 

 its isolation by right and not in consequence of a 

 practical interest on the part of the investigator who 

 contrives it ? Some points in the article illustrate 

 how doubtful this is. Sir Oliver attaches prime 

 importance to the aether of space as a scientific 

 explanation ; would he class it as a scientific or as 

 a philosophic problem ? How can it be discussed 

 without reference to the infinity of space, which is 

 a question the man of science is to leave to the 

 philosopher ? Again, as an example of scientific 

 deduction and prediction we are given the discovery 

 of Neptune, but we are not told where to place or 

 how to explain the failure to discover Vulcan. 



Oat Straw as a Cattle Food. — S. H. Collins 

 and B. Thomas have an interesting paper in the 

 Journal of Agricultural Science, vol. xii. pp. 280-286, 

 1922, upon " The Sugars and Albuminoids of Oat 

 Straw." The authors set out to answer a question 

 that first occupied the attention of one of them 

 twentv-two years ago. " Why can cattle be fattened 

 on roots and straw in Scotland and not in England ? " 

 Limitations of time apparently prevented the prosecu- 

 tion of experimental work then, and in the last 

 twenty vears there has been considerable develop- 

 ment in our knowledge of animal nutrition, so that 

 the authors can now attack with considerable 

 precision the question as to whether the nutrients 

 available in the straw will supplement the deficiencies 

 of grain feeding. The answer appears to be that 

 good oat straw, mainly owing to its relatively high 

 percentage of albuminoids, may well do this, but 

 oat straw has been found to van' in this percentage 

 between 1-12 and 8-05. The low percentages are 

 usuallv for the straw from the south of England, 

 the high from Scotland ; this may be, in part, a 

 question of latitude, but the high figures for Cumber- 

 land and Westmoreland, and the values for differently 

 manured crops, lead the authors to think that good 

 husbandrv and suitable supplies of organic nitrogen 

 are even more important. These investigations 

 certainly seem to bring the original question ap- 

 preciably nearer solution. An interesting point in 

 the sugar estimations reported is the fact that the 

 main sugar of the straw appears to be laevulose, 

 while the main digestible carbohydrate constituent 

 of the grain is the dextrosan starch. If the ideal 

 carbohydrate for nutrition be cane sugar, then this 

 is an additional argument for the good straw proving 

 a valuable supplement to the grain ration. 



NO. 2774, VOL. I IO] 



Deep Root Systems of Crop Plants. — The diffi- 

 culties attending the study of the root systems in 

 situ has led to a comparative neglect of this important 

 branch of research until recent years. Prof. J. E. 

 Weaver, F. C. Jean, and J. W. Crist, in the " Develop- 

 ment and Activities of Roots of Crop Plants" (Car- 

 negie Institution of Washington, 1922), are to be 

 congratulated on realising the urgency of this prob- 

 lem. The value of this work is much enhanced by 

 the numerous sketches of actual root systems made 

 during excavation, together with full details of en- 

 vironmental conditions and experimental results. Re- 

 peated investigations at various stations indicate that 

 all cereals possess two distinct groups of roots, one 

 spreading in a more or less horizontal direction in the 

 upper layers of soil, and the other penetrating deeply 

 into the "subsoil to a depth -of six or seven feet. The 

 lower roots are often much branched and appear to 

 be of the normal absorbing type. In potatoes, on 

 the other hand, the original shallow roots turn verti- 

 cally downwards and form the deeper portion of the 

 system. As a general rule, only the first six or eight 

 inches of soil are regarded as being of much value in 

 plant nutrition, but controlled experiments indicate 

 that these deep roots play a great part in water 

 absorption, as much or more water often being re- 

 moved from a depth of three feet as from the surface 

 layers. Maize was proved to absorb large quantities 

 of" water from the fifth foot. It was similarly shown 

 that such fertilisers as nitrates were freely removed 

 from the lower soil depths, to five feet in the case of 

 maize, and at least two and a half feet with barley 

 and potatoes. Furthermore, when roots came into 

 contact with a fertilised layer they developed more 

 strongly and branched more profusely, and at the 

 same time normal penetration into the soil below was 

 apparently retarded. The depth at which manures 

 are placed in farm practice must therefore have a 

 considerable effect on root development, and surface 

 applications during times of drought may be \ < ry 

 detrimental by keeping the roots from penetrating 

 into the deeper layers with greater water supply. The 

 authors conclude "that " the deeper soils are not only 

 suited to plant-life, but that they play an exceedingly 

 important part in the life of the plant, and deserve 

 careful consideration in a study of crop production." 



Bottom-living Communities in the Sea. — A very 

 full account of the biology of the Danish Crustacea, 

 Gammarus locusta, and Mysis inermis, flexuosa and 

 neglecta, is given by H. Blegrad in the twenty-eighth 

 Report of the Danish Biological Station (Copenhagen, 

 1922). The work has interest in connexion with 

 Dr. Petersen's studies of bottom-living communities 

 in the sea. It is not nearly enough that the numbers 

 of animals inhabiting a unit area should be known ; 

 some good estimates of the rates of reproduction and 

 the number of generations that occur throughout a 

 year, for example, are necessary if we have to attempt 

 a measure of the productivity of a sea-bottom area. 

 The object of the memoir under notice is to supply 

 some information on these subjects. 



Molluscs oe the Colorado Desert. — Dr. S. S. 

 Berry's notes (Proc. Acad. Nat. Sci. Philadelphia, 

 lxxiv. 1922, pp. 69-100) on the molluscs of the 

 Colorado Desert include short descriptions of speci- 

 mens belonging to eight genera, most of them repre- 

 sented by a single species, but one genus (Micrarionta) 

 is represented by five species, two of which are new. 

 This land snail fauna is confined to the steep mountain 

 slopes, while the fresh-water mollusca are centred 



