ll November 3, 1910] 



NATURE 



25 



unined the extract in detail, and the great value of his 

 rk is that he is dealing with definite varieties of oats 

 \vn under known conditions. It is understood that the 

 research is being continued, and some interesting con- 

 clusions may be looked for. 



Mr. A. S. Home gave an account, illustrated by photo- 

 phs, of a bacterial disease of potatoes. Not long ago 

 was supposed that plant diseases were caused by fungi, 

 but cases are steadily accumulating where bacteria are 

 the active agents. Several cases have been worked out at 

 Newcastle, and it was felt that on a future occasion more 

 time will have to be devoted to this important branch of 

 study. 



The second day was given up to a discussion of two 



subjects now coming much into prominence. Sugar-beet 



growing was dealt with by Mr. Sigmund Stein and Mr. 



; G. L. Courthope, M.P. Later in the day nitrogen fixation 



was discussed by Mr. Golding and Prof. Bottomley. It has 



. always been known that sugar beet could be grown in 



England, but the industry never had an opportunity of 



development by reason of the Continental sugar bounties. 



The Brussels Convention, however, has so altered the 



-:iion of affairs that a reasonable prospect of success 



:!s assured ; already factories are springing up in 



(iinerent parts of the country, and farmers are contracting 



to supply the necessary beets. For many years Mr. Stein 



Hie; advocated beet-sugar production, and in his paper he 



a summary of the various experiments he has made to 



t the objections that have from time to time been 



raised. He claimed that the practical difficulties, both in 



; the field and the factory, are now overcome, and the time 



is ripe for active development. Mr. Courthope dealt with 



' the financial aspects of the question, and gave a number of 



carefully prepared statistics showing that the new industry 



1 has every probability of success. This paper created a 



jvery favourable impression, and the speakers that followed 



: agreed that a good case had been made out. There has, 



as usual, been a good deal of exaggeration about the 



possible effect of a new rural industry. If sugar beet is 



grown, some other crop will have to go out ; the gain to the 



country will therefore be the difference between the new and 



the old, and not, as is commonly stated, the whole amount 



; that the new crop will bring in Still, there is no doubt 



that a new industry and a new market would have a useful 



! steadying effect on agricultural prices. 



I Nitrogen fixation was the next subject. Prof. Bottomley 

 I brought forward the evidence in favour of his proposition 

 •that .Azo:obact('r, in coniunction with Pseudomonas. both 

 obtained from the root tubercles of Cycas, will " fix " more 

 I nitrogen than either alone. He further argues that this 

 j mixed culture will grow in soils and " fix " nitrogen to 

 ' form compounds readily transformable into plant food. 

 Some discussion arose as to the interpretation of the 

 results ; the quantities involved are small, and the experi- 

 mental errors known to be considerable. The great diffi- 

 culty arises, however, in the absence of a satisfactory 

 : standard by which one experiment may be compared with 

 I another. 



I Mr. Golding dealt with his subject in a more general 

 way, his researches having been directed to the whole 

 question of nitrogen fixation in the root nodules of 

 leguminous plants. This fixation is brought about by 

 bacteria which invade the root hair as infection threads, 

 pass through a rod-shaped stage, and finally assume the 

 bacterojd (Y) form. Mr. Golding is steadily overcoming 

 the difficulties of working with the organisrn in artificial 

 media, and is succeeding in making it pass through the 

 changes that it undergoes in the plant. During the period 

 of active nitrogen assimilation an alkaline substance is 

 formed ; after a time, if the products are not removed, 

 assimilation stops, the alkali disappears, and the medium 

 becomes acid. Dr. Russell pointed out that this change 

 from alkaline to acid reaction indicated that the organisms 

 were now utilisine: the nitrogenous base alreadv formed, 

 and therefore setting the acid free, a change known to go 

 on in other cases. 



On Monday. Seotember 5, a joint meeting was held with 

 the Zoological Section to discuss the effect of partial 

 sterilisation of soils. Dr. Russell read a paper which he 

 and Dr. Hutchinson had orepared, giving an account of 

 the work they have been doing at Rothamsted during the 

 past three years. There is a notable increase in productive- 

 NO. 2140, VOL. 85] 



ness when a soil is heated or treated with volatile antiseptics- 

 like toluene. This was traced to an increase in bacterial 

 activity, which, in turn, was shown to be the result of 

 removing some factor that had in the original soil limited 

 bacterial activity. By drawing up a systematic plan of 

 experiment it was possible to find what processes would, 

 and what would not, put the injurious factor out of action, 

 and so the authors had arrived at a list of properties the 

 factor possessed. .According to their results it appears to^ 

 be a living organism larger than bacteria, but developing, 

 more slowly, killed at or below 50° or by prolonged 

 drought. It might actively destroy bacteria, or, on the other 

 hand, it might form a protoplasmic layer round the soil 

 particles containing organic matter, and thus keep off and 

 starve the bacteria. Tne zoologists present made some very 

 useful suggestions. Dr. Shipley recommended sewage-farm 

 soils as the best place to start hunting for the organism. 

 Dr. Ashworth suggested that the amoebae or amoeboid 

 organisms of the soil might be the culprits, and considered 

 that methods of investigation like those used by Musgrave 

 and Clegg or by Noc might with advantage be tried. Mr.. 

 T. J. Evans, on the other hand, thought that the results 

 indicated a mycetozoan Plasmodium, while Mr. J. J. Lister 

 urged that mycetozoa would require vegetable matter, which, 

 however, they would have in the soil. 



Mr. K. J. J. Mackenzie followed with an account of the 

 " fKDints " prized by the breeder of high-class stock, and 

 gave the results of measurements he had made to find out 

 how far the " points " really are correlated with the 

 characters they are supposed to indicate. So far as he has 

 gone — he is pursuing the problem further — the correlation. 

 is very slight, and it can only be inferred that the breeder 

 arrives at his eminently successful results rather by an 

 intuitive process than by any use of his "points." The ques- 

 tion is of great economic importance, because England is, 

 and seems likely to remain, the stud-farm of the world. 



A joint meeting with tlie Geological Section followed, at 

 which soil sur\eys were discussed. .\ paper by Mr. HalL 

 and Dr. Russell was read, dealing with the objects and 

 methods of agricultural soil surveys. The ordinary drift 

 map is not sufficient, although it makes an admirable 

 starting point. It is necessary to classify the soils further, 

 to studv them in their relation to the local agriculture, and' 

 to ascertain the effect of manures, of rainfall, topographical 

 position, &c. Illustrations were given to show that a soil 

 may be sufficiently described from the agricultural point of 

 view when its mechanical analysis, and its positions on 

 the geological, orographical, and rainfall maps are known. 

 Mr. L. F. Newman gave a preliminary account of his 

 survey of the drift soils of Norfolk, which seems to indicate 

 a fairly regular distribution of the various types of soil. 

 Mr. C. T. Gimingham described the " teart " land of 

 Somerset, on which animals " scour " badly. This con- 

 dition is confined to one formation, the lower lias, and 

 disappears when even the most superficial covering of 

 alluvium occurs. \ large acreage is affected. Evidence is 

 adduced that the cause is to be sought in the physical state 

 of the soil ; if this is so, it should be capable of remedy. It 

 is much to be hoped that the field trials which Mr. Giming- 

 ham has drawn up to test this view will be carried out. 



The last day opened with a paper by Mr. Hall on the 

 cost of a day's horse labour on the farm. This funda- 

 mental problem of agricultural economics has been but 

 little investigated, and Mr. Hall's estimate of 25. "jd. per 

 dav must be regarded as the most complete we have at 

 present. Another economic paper followed, by Mr. Turnor, 

 on costs in the Danish system of dairy farming. The data 

 were gathered during a tour of Denmark, and represent a 

 good deal of study of the subject. Mr. Turner is shortly- 

 bringing out a book in which the results of his investiga- 

 tions will be more fully dealt with. 



The rest of the dav was devoted to a discussion jointly 

 with the Economic Section of the errors of agricultural 

 experiments. Prof. Wood opened the subject with three 

 papers prepared in conjunction with Messrs. Stratton and 

 Bruce. From the results it appears that many of the 

 feeding trials carried out in the country are of very 

 doubtful value. Agriculturalist.*; have usually neglected the 

 experimental error ; in few, if any, of the numerous county 

 council experiments, for instance, is it ever taken into 

 account. Prof. Wood's papers, along with one by Mr. Hall 

 and Dr. Russell on field trials, have emphasised the import- 



