50^ 



NATURE 



[October 20, 1910 



was echoed most eloquently by M. Bourgeois, the presi- 

 dent of the conference. 



Prof. Landouzy, introducing the first subject for dis- 

 cussion, the influence of predisposition and heredity, 

 claimed that these were almost as important from the 

 practical point of view as was the bacillus of Koch itself. 

 He maintained that the tubercle bacillus in the parent 

 might act in one of two ways, either by direct passage 

 from the parent to the offspring, or by some toxic action 

 on the ovum or upon the foetus. He pointed out that these 

 two sets of conditions were necessarily perfectly distinct, 

 but maintained that the latter was of far more importance 

 than the fo.'mer, and that it accounted for the peculiar 

 tubercular diathesis so frequently met with in patients. 

 His thesis was that the subjects of this diathesis are 

 degenerates who may " come into the world before their 

 time, are under weight, short in stature, with thin, 

 delicate bones, flattened chests, a skin delicate and soft, 

 small extremities, pale and sickly face, veins very trans- 

 parent, hair prematurely developed, long eyelashes, glands 

 easily enlarged, aspect w:akly." Such characteristics he 

 has found specially amongst his tuberculous patients, and, 

 curiously enough, this is exactly the type taken by the 

 Venetian masters for their models, in whom we see silky 

 golden or red hair, pale, transparent, and delicate freckled 

 skin. This Venetian type, mr rufits, he maintained, was 

 specially subject to tuberculosis. Moreover, animals with 

 non-pigmented coats appeared to be more susceptible to 

 tuberculosis than those of darlier skin. In the discussion 

 that followed it was agreed that tuberculosis was seldom 

 communicated directly from mother to child, but that a 

 certain transmitted functional debility might leave the 

 child open to the ready invasion of various causes of 

 disease and death, and that in this transmission the 

 mother played a more important part than the father. It 

 was suggested, however, that it was a very difficult matter 

 indeed to demonstrate experimentally any predisposition, 

 native or hereditary, to tuberculosis, though this was a 

 matter that required further consideration. 



The natural portals of entry were considered to be 

 the lungs, the mucous membranes of the throat, the 

 .tonsils, the intestinal mucous membrane, and the 

 epidermis, whilst the lymphatic glands were looked upon 

 as playing u great part in sifting out and destroying the 

 bacilli, though as they become lowered in vitality and no 

 longer able to cope with the tubercle bacilli they may be 

 broken down, and the scrofulous condition results. 



Prof. Calmette, in speaking of the special susceptibility 

 of children of tuberculous parents, said that this 

 receptivity was not specific as regards tuberculosis, but 

 applied generally to various infections and intoxications. 

 The predisposed of the clinicians, he maintained, are 

 vrry often the subjects of infection already. They are, he 

 thinks, more or less gravely affected, especially as regards 

 the lymphatic glands, and in almost all cases react posi- 

 tively to the various tuberculin tests. Moreover, he finds 

 that if in place of tuberculin he injects mallein, he obtains 

 a marked loss of weight. The stigmata of tuberculosis 

 appearing at certain ages are, he thinks, the result of 

 earlier infections, for he found that of children coming 

 up to be vaccinated 90 per cent, of those from the town 

 of Lille are already infected with the bacillus of tubercu- 

 losis even in cases where no definite lesions are developed, 

 whilst in one lunatic asylum he found no fewer than 87-68 

 per cent, of the patients giving the skin reaction, so that 

 if they were not already tuberculous they were already the 

 bearers of the tuberculous germs. 



Other speakers laid stress on tissue predisposition ; on 

 the marked respiratory changes th.it occur, not only in 

 tuberculosis, but in other acute diseases ; on the low 

 arterial tension observed in those predisposed to tubercu- 

 losis ; and on the importance of the observation that in 

 cases where recovery took place pigmentation was both 

 rapid and complete, whilst in those that succumbed such 

 pigmentation did not occur. 



One speaker, M. Fiery, agreed that the offspring of 

 tuberculous parents are undoubtedly specially liable to 

 tuberculosis, and that the types of the disease in these 

 patients are very varied, but on the other hand ho thinks 

 that a certain proportion of such offspring are actually 

 immune, and that these patients, immune to a grave 

 tuberculosis, are just the types in which the so-called 

 NO. 2138, VOL. 84] 



stigmata of hendiiary predisposition are present. More- 

 over, he believes with M. Calmette that many of the 

 patients with these " stigmata of hereditary suscepti- 

 bility " are really already suffering from the disease. 



It seemed to be the general opinion that small numbers 

 of slightly virulent tubercle bacilli taken into the alimen- 

 tary canal might in certain cases act as immunising 

 agents, but that in larger numbers and in virulent form 

 they might set up typical lesions, especially in susceptible 

 animals ; that botlr immunity and predisposition might 

 arise from the same cause, the bacilli in the one case 

 setting up a kind of negative phase, in the other a positive 

 phase, and that until the conditions under which these 

 two phases are produced had been settled it was difficult 

 to determine the part played by heredity in immunising 

 or predisposing to the action of the bacillus. 



Of the English delegates, Dr. Nathan Raw said that, 

 as the result of an analysis of 232 cases of tuberculosis 

 that had terminated fatally, he found that pulmonary 

 tuberculosis was most frequently brought about first by 

 direct inhalation of the Bacillus tuberculosis into the 

 bronchioles ; secondly, by extension from a bronchial 

 gland to the parenchyma of the lung, this being specially 

 associated with or following an attack of some acute 

 infective fever such as measles, scarlatina, or diphtheria ; 

 by extension upwards from the abdomen by the diaphragm 

 to the bronchial glands, and then to the lungs ; by 

 extension downwards from the glands of the neck directly 

 to the pleura, and then to the apex of the lung ; and, 

 finally, by a general infection of the circulating blood, as 

 in acute miliary tuberculosis. 



Dr. C. Theodore Williams, following, insisted uf>on the 

 importance of predisposition and on the wisdom of trying to 

 ascertain the conditions of the human system which cause 

 disposition to tubercle, and, conversely, those which confer 

 immunity from tubercle. Analysing 1000 cases of con- 

 sumption that occurred in the upper classes, he finds that 

 the age of attack is earlier amongst females than amongst 

 males, and that amongst males affected by hereditary 

 predisposition it is earlier by three years than among those 

 free from hereditary predisposition, and in females by six 

 and a half years. Similarly analysing 400 consumptive 

 cases seen in the out-patient department of the Brompton 

 Hospital, he found that his former conclusion as regards 

 the age of attack being hastened on by family predispo- 

 sition was confirmed, though here the relative influence 

 on the two se.xes differs greatly from what was noted in 

 the richer classes. Among the out-patients, the age of 

 attack was about the same for male as females, the males 

 being attacked earlier than among the rich, the females 

 later. The age of attack in those free from family taint 

 was later in both sexes, and the predisposition influence 

 greater in the male than in the female. 



One or two of the later speakers were of opinion that 

 although many of the points raised that afternoon were 

 of undoubted interest and of great importance to the 

 individual, it was somewhat inadvisable to lay too much 

 stress on this question of predisposition, except in so far 

 as it pointed to the necessity to keep these patients out of 

 the range of the attack of the tubercle bacillus. Of course, 

 it was useful in connection with both prognosis and treat- 

 m.ent, but at present the campaign must be carried on on 

 a large scale against the tubercle bacillus and to remove 

 the conditions under which it does its work most 

 effectively, the predisposition being taken up specially in 

 connection with the raising of the standard of health and 

 of improving general hygienic conditions. There seemed 

 to be some danger that the importance of the rdle of 

 Koch's bacillus might be overshadowed in the popular 

 mind, and it appeared to be necessary to insist that, 

 although the tubercle bacillus does not always set up 

 tuberculosis, no tuberculosis is ever set up without the 

 presence of the tubercle bacillus. If heredity and predis- 

 position are to be put so prominently forward, those who 

 are dealing with the question might sometimes lose heart. 

 At the same time, the acknowledgment that they may 

 play a part should be followed by a call to the physician 

 to look after the building up and strengthening of the 

 patient. Then, again, it was always well to point out 

 that on the one hand many blondes escape tuberculosis, 

 whilst those richer in pigment, the negroes, are often 

 affected, sometimes evincing even a higii predisposition. 



