6i4 



NATURE 



[January 6, 192 1 



taufjht us that this is not a diseased state, but a pur- 

 poseful reaction against injury, gradually perfected in 

 passing up from the lower to the higher animals. 

 Almost without our being conscious of it, the idea of 

 evolution has gradually etfected a great change in the 

 point of view from which we regard a large number of 

 diseases, the symptoms and morbid changes in which 

 we now understand as elTorts of the body to maintain 

 its integrity in face of the injurious agencies which 

 threaten it. One might almost rewrite pathology 

 from the evolutionary point of view 



Last, but not least, of the great changes which 

 have swept over medical science is that which was 

 due in the first place to Pasteur, carried on by 

 Koch, and brought to triumphant practical applica- 

 tion by Lister. The discovery of the true nature of 

 infection has of necessity transformed the outlook of 

 medicine and surgery, but bacteriology and its 

 daughter science immunology would demand a 

 Harveian oration to themselves. 



We looselv speak of such fundamental discoveries 

 as those I have just mentioned as producing a revolu- 

 tion in medical science. It is not revolution, but 

 upward growth. With the establishment of each 



great principle we gain a fresh height from which the 

 field of science takes on a new and wider aspect, and 

 we may be confident that we shall reach yet greater 

 heights to reward us with an even ampler range of 

 vision. There is no sign that the vitality of science 

 in our civilisation is in any way spent ; on the con- 

 trary, its fertility is unchecked. During the late war 

 we saw for the first time the scientific forces of th: 

 country fully mobilised, and no previous five yeai 

 have seen so many .scientific problems brought to a 

 successful issue. So forcible has been the lesson that 

 science has gained mightily in public estimation, and 

 research is on the lips of everyone. New facts are 

 being gathered in, old facts are coming to be seen 

 in a new light ; we are almost bewildered by our own 

 progress. The workers in the field of medical scienc • 

 are many, and it may not be given to any one of i. 

 to make an immortal discovery, such as that of th 

 circulation of the blood. But the humblest of us ca: 

 work in Harvey's spirit and bring his contribution tu 

 the building up of knowledge in the full assurance 

 that even a single stone, if honestly and truly 

 squared, will in due time find its proper place in 

 the fabric. 



Wheat from Seed-bed to Breakfast-table. 



" T'HE History of a Grain of Wheat from the Seed- 

 ■^ bed to the Breakfast-table" formed the subject 

 of the concluding evening discourse given by Sir 

 Daniel Hall at the Cardiff meeting of the British 

 Association, and an account of it appeared in the 

 October issue of the Journal of the Ministry of Agri- 

 culture. Of all industries there is not one which is 

 older, more universal, or more essential than the 

 growing, grinding, and baking of wheat and its 

 kindred food-grains. Yet, in spite of the extreme age 

 of the industry, the various processes involved in the 

 passage of the wheat-grain from its seed-bed to the 

 breakfast-table still demand the close attention of the 

 best obtainable research men of the day; for it is 

 onlv by research and by the utilisation of the results 

 so obtained that the increased food production neces- 

 sary for supplying the needs of the world's growing 

 population can be attained. 



Manv experiments have been made to try to bring 

 about an increase in yield by treating the seed either 

 bv electricity or by soaking it in some nutrient fluid. 

 The results of these experiments are very doubtful, 

 and it is improbable that such treatment can affect 

 the ultimate yield. .Attention has also been paid to 

 the influence on the wheat yield of the rate of sowing. 

 Ordinarilv, wheat sown at the rate of 2^ bushels per 

 acre gives a thirteenfold yield, but isolated wheat- 

 plants are capable of giving more than a hundredfold 

 yield. It is hoped that by using a suitable machine 

 a perfectly effective seeding can be attained with 

 1 bushel per acre, and such a reduction in the amount 

 of seed sown would mean a considerable gain to the 

 countrv. ■ Improvement in the quality of wheat grown 

 has been brought about by careful breeding work. 

 Prof. Biffen, working on. Mendelian principles, has 

 obtained a variety of wheat, "Little Joss," which 

 produces very good crops on certain soils because of 

 its resistance to rust attacks, the rust-resistance power 

 having been introduced into the grain by careful selec- 

 tion and breeding. .-Xnother wheat, "Yeoman," has 

 been bred for the high milling quality of the grain, 

 and on soils to which it is suited the " Yeoman " 

 wheat yields a very heavy crop, while the quality of 

 the flour is almost equai to that obtained from the 

 best Canadian grain. -At the present time millers art 

 compelled to mix strong foreign wheat with our home- 

 NO. 2671, VOL. 106] 



grown wheat in order to produce bread of the spon:^ 

 type desired by the public, but it is hoped that exter, 

 sion of Prof. Biffen 's work will ultimately suppl 

 strong wheats of the "Yeoman" type suited to th. 

 varying conditions of all our different wheat-growing 

 districts, and in this way the millers may be rendered 

 independent of foreign wheats. 



Although wheat is the crop for breaking in virgin 

 land, yet it will not stand competition ; at Rotham- 

 sted a wheat crop left unharvested to sow itself with- 

 out further cultivation entirely disappeared in a grassy 

 wilderness in three years. Wheat, though thus 

 dependent on cultivation, possesses a remarkable 

 power of yielding a good crop upon all sorts of soil. 

 One of the Rothamsted plots has carried wheat for 

 seventy-seven successive years without any manuri , 

 and the yield is still about 12 bushels per acre — 

 approximately the average crop for the wheat-lands 

 of the world. The manurial requirements of a wheat 

 crop have long since been decided, and the problem 

 now is to prevent the lodging which occurs with big 

 crops on good soils. It may be possible to breed 

 varieties with stiffer and shorter straw, or it mav be 

 that manurial treatment, time of sowing, widtfi of 

 rows, and spacing of the seed have some effect on the 

 lodging, or, again, there may be some actual disease 

 factor involved. -Ml these points are being inves- 

 tigated. 



The growth of the wheat-plant, so far as gathering 

 material from the air and from the soil is concerned. 

 is practically completed about five weeks before thr 

 grain is harvested. This latter period is occupied by 

 the transference of stored-up food from the leaves 

 and stem to the seed. The transference, however, is 

 never complete, and the straw still retains about half 

 of the valuable material manufactured by the plant 

 Since the amount of such material depends largeh 

 on conditions of soil and water-supply, which are out- 

 side our control, one line of development must be to 

 increase the migration into the seed. This is 

 especially urgent in drier countries where insufficient 

 water-supplv sets a definite limit to the amount of 

 growth. With regard to the flour, considerable 

 differences in milling operations have been brought 

 about under the stress of war. The miller's object 

 is to crack the wheat "berrv " with the least possible 



