August 26, 1922J 



NA TURE 



2 93 



The Glasgow Meeting of the British Medical Association. 



' [ " HE ninetieth annual meeting of the British 

 ' Medical Association was held in Glasgow on 

 July 25-28, under the presidency of Sir William 

 Macewen, and its proceedings included much of 

 interest to men of science outside the circles of 

 medical specialism. In his address delivered on the 

 evening of July 25 in the Bute Hall of the University, 

 after welcoming the Association to Glasgow and refer- 

 ring to some of the great names associated with the 

 University of Glasgow during the 471 years of its 

 existence, the president put in a strong plea for a 

 broader scientific outlook with less concentration on 

 purely human phenomena. He referred to the want 

 of scientific training and scientific habits of thought 

 in the general community, and pointed out how this 

 had led to the neglect of discoveries of the greatest 

 practical importance. It had now been discovered 

 that such a disease as syphilis was a preventable germ 

 disease, which could be stamped out by means made 

 known to them : "If this generation did not stop the 

 disease it committed a crime against posterity." The 

 main part of the address dealt with the enthralling 

 subject of brain-surgery, of which the speaker is one 

 of the most distinguished pioneers, and of which he is 

 still an acknowledged master. 



On the following three days the Association met in 

 separate sections, housed in the medical and scientific 

 departments of the University, and in various of 

 these papers were read and discussions held which 

 were of wide scientific importance. In the section of 

 pathology an interesting discussion took place on 

 " Animal and Vegetable Pathology in Relation to 

 Human Disease," the openers being Prof. Hobday 

 and Prof. Lang. The former dealt mainly with the 

 importance of diseases communicable to man, such as 

 glanders, rabies, anthrax, and tubercle. Prof. Lang 

 discussed in a more general way the relations of 

 vegetable pathology to animal, tending on the whole 

 to sound a note of caution against the assumption 

 that the principles underlying the processes of disease 

 and healing are identical in the two kingdoms. He 

 discussed the case of crown gall, on which important 

 recent work had been done by Smith and Townsend," 

 and by Robinson and Walkden. In this case tumours 

 developed in relation to wounds such as those made 

 in grafting, and it had been shown that the new growth 

 was due to infection by a specific microbe Bacterium 

 tumefaciens. The fundamental differences in organisa- 

 tion between the higher animal and the higher plant 

 should, in Prof. Lang's opinion, be carefully borne in 

 mind before instituting close comparisons between 

 such tumours caused by B. tumefacium and the 

 malignant new growths of man. The probability 

 was that the pathogenic processes of plants and 

 animals had begun to diverge from one another at a 

 very remote period of evolutionary time, and the 

 value of the study of plant pathology to the human 

 pathologist (and incidentally to the student of 

 medicine) lay rather in its broadening the outlook 

 than in its providing the bases for direct inferences 

 from one subject to the other. In the course of his 

 paper Prof. Lang referred to the fact that the study 

 of ancient plants obtained from the Old Red Sand- 

 stone of Scotland had disclosed injuries, due ap- 

 parently to irritating gases, and healing processes, 

 bearing the closest similarity to what may be observed 

 in modern plants after exposing them to irritating 

 vapour. This fact is obviously of extraordinary 

 biological interest as being the most ancient case of 

 pathological reaction which has been subjected to 

 histological investigation. 



The discussion just mentioned had its supplement 



NO. 2756, VOL. I io] 



on the following day in the new but highly successful 

 section of micro-biology, sitting under the' presidency 

 of Dr. R. M. Buchanan, when Prof. V. H. Blackman 

 opened a discussion on " Some Similarities and Dis- 

 similarities in the .Micro-biology of Plant and Animal 

 Diseases." Prof. Blackman also was inclined to 

 emphasise the differences rather than the resem- 

 blances between the diseases of plants and animals. 

 He gave an interesting general review of the relations 

 of parasite and host in the parasitic diseases of plants. 

 The immunity of plants towards hostile micro- 

 organisms was a natural immunity : the acquired 

 immunity so characteristic of many human diseases 

 and forming the basis of modern serum-therapy was 

 quite unknown in relation to specific diseases in 

 plants. Immunity was often of a passive kind, such 

 as is provided by a resistent enticle or cell-wall, 

 successful invaders in such cases making their way in 

 through natural openings such as the stomata, or 

 through special perforations made by their own 

 activity. In other cases the immunity was of an 

 active kind, involving a distinct physiological reaction 

 on the part of the plant. Thus in cereals immune 

 to " rust " the cells have developed a hyper-sensitive- 

 ness to the proximity of the fungus, dying upon its 

 approach, before they can be penetrated bv the 

 parasite. In other cases the host imprisons the 

 invading parasite in an envelope of impermeable cork 

 cells. Prof. Blackman also directed attention to the 

 existence amongst plants of diseases due to so-called 

 ultra-microscopic organisms. Two diseases of this 

 type occurring in the potato had recently been found 

 to show a further analogy with diseases of a similar 

 type occurring .in animals in that they were insect- 

 borne, being transmitted by aphides or green-fly. 



The " ultra - microscopic " or " filter - passing " 

 organisms were also to the fore at other meetings of 

 the section of micro-biology. On Wednesday, July 

 26, Dr. F. d'Herelle, of the Pasteur Institute, opened a 

 discussion on his theory of " Bacteriophage " — a 

 theory formulated to explain the fact that among the 

 contents of the alimentary canal there always exists 

 a " something " which possesses the power of dis- 

 solving bacteria of certain definite types, e.g. in the 

 case of man bacteria of the coli-typhoid-dvsentery 

 group. This " something," sometimes called an 

 enzyme, sometimes given the more definite name 

 bacteriolysin, is of uncertain origin. The balance of 

 probability would probably appear to most biologists 

 to be in favour of its being formed by the activity of 

 the host, its formation being part of the general 

 defensive mechanism of the body. Dr. d'Herelle, 

 however, believes it to be formed by an ultra-micro- 

 scopic enemy of the bacteria, which he names Bactei io- 

 phagum intestinale, and he supports his theory by a 

 mass of striking arguments. Dr. Twort, of the 

 Brown Institute, gave an account of his earlier work, 

 in which he determined the existence of a similar 

 bacteriolytic substance in cultures of microcoi 

 point of much interest emphasised by Dr. Twort, but 

 usually ignored by biologists, is the probability that 

 ultra-microscopic organisms exist in abundance free 

 in nature, and are not confined to a parasitic existence. 



In the discussion on Thursday, July 27, upon the 

 " Bacteriology of Influenza," an important role was 

 again assigned to the ultra-microscopic type of 

 organism. Dr. Mervyn Gordon recalled that a large 

 number of diseases, such as measles, mumps, small- 

 pox, were now attributed to these organisms, measur- 

 ing under 0.5^ in diameter, to which Prowazek had 

 given the name Chlamydozoa. Strong evidence had 

 recently been adduced that the real causative agent 



