82 



NATURE 



[July 20, 191 1 



The answers lo the questions, though very guarded 

 in many directions, are, where the Commissioners 

 have made up their minds, clean cul and definite. No 

 pretence is made to answer anj questions bul those 

 contained in the reference, and anyone going to this 

 Reporl for general information on the subject of 

 tuberculosis generally will come away greatly dis- 

 appointed, but on the question-, the Commission was 

 asked to answer the expert will find ample material 

 for thought. 



Is the disease in animals and man one and the same.' 



Before this question could be answered the Com- 

 missioners had apparently to satisfy themselves that 

 the tubercle bacilli found in animals (especially 

 bovine) and man (a) were the same, morphologically, 

 culturally, and pathogenetically ; or (b) they differed 

 in one or other or all of these aspects, and, if they 

 differed, whether any modification of these aspects ever 

 occurred under either natural or artificially produced 

 conditions. 



The conclusion at which the Commissioners arrive 

 is that it is practically impossible to differentiate the 

 bacillus found in the bovine animal suffering from 

 tuberculosis from that found in certain cases of tuber- 

 culosis in the human subject. The bacilli are alike in 

 every respect — morphology, cultural characters, and 

 virulence. In the human subject, however, especially 

 in eases of pulmonary tuberculosis, a tvpe of tubercle 

 bacillus occurs which', though resembling morphologi- 

 cally that found in bovines suffering from tuberculosis, 

 differs considerably in cultural characters — e.g., rate 

 of growth on artificial media and in virulence. 

 Both types produce rapidly progressive tuberculosis in 

 the human subject and certain other animals, but 

 only one, the bovine type, is specially active when 

 introduced into the bovine animal. It is obvious, then, 

 that wherever a tubercle bacillus is found, it may set 

 up tuberculosis in the human subject, whatever it 

 may be able to do in the cow. Moreover, the disease, 

 when set up in the human subject, always runs much 

 the same course, whither the exciting agent in its 

 production is the one form of the bacillus or the other. 



The answer to the second term of reference — 

 "Whether animals and man can be reciprocallv in- 

 fected with it " — follows as a kind of corollary. There 

 is ample evidence put forward to prove that many 

 ease, ,i| fatal tuberculosis in the human animal 

 (usually in children) have been set up by the bacillus 

 proved to have been the cause of the disease in 

 bovines. On the other hand, the type found jiaturally 

 only in the human subject appears to set up in the 

 bovine merely a non-progressive tuberculosis. It was 

 found, however, that adult human beings are some- 

 times infected by the tubercle hacillus of bovine tvpe, 

 1 ' - 11 the lungs becoming involved, whilst it is evident 

 hum recorded experiments that cattle have not by any 

 means complete insusceptibility to the attacks of the 

 tubercle hacillus of human type. These facts are of 

 priman importance when, as is evident from the work 

 recorded, there are such gradations in all the differen- 

 tiating characters in many of the strains of bacilli 

 separated from ordinary cases of tuberculosis in the 

 human subject — a gradation that becomes even mote 

 marked and important in the groups of bacilli isolated 

 (a) from the lesions in cases of lupus and (hi from the 

 tuberculous in the horse. 



Granting that the foregoing may be accepted, ii 

 follows that the third term of reference concerning the 

 conditions under which transmission of the disease 

 from animals to man lakes place can onh be answered 

 throusrh a study of the susceptibility (a) ol thi animal 

 and (b) of man. The susceptible individual, whether 

 brute or human-, will be most affected, and by the 

 widest range of tubercle bacilli as regards gradations 

 NO. 2177, VOL. 87"! 



of virulence. Each individual affected will constitute 

 a centre of infection, and the greater the number of 

 these susceptible individuals exposed even to "weak 

 infections," the greater the chance of further trans- 

 mission ot the disi ase. It would appear that resident 

 ol a tubercle bacillus in .any animal or series of 

 animals for a considerable length of time may in- 

 crease the virulence of that bacillus for the special 

 species in which it is "cultivated." This certainly 

 occurs in connection with other micro-organisms — 

 e.g., the pyogenic streptococci and certain forms of 

 micro-organisms giving rise to septicemic processes 

 — still no direct evidence is adduced by the Commis- 

 sioners that this takes place in connection with the 

 tubercle bacilli, though in the course of their work 

 they came across an enormous varietj ol grades of 

 virulence in the tubercle bacilli from various sources 

 in man and the lower animals. The bovine tvpe of 

 bacillus occurs with such frequency in children, especi- 

 ally in sites connected with the alimentary canal, that 

 it seems impossible to ignore the causal relationship 

 between tubercle bacilli found so frequently in the milk 

 given by tuberculous cows and the tubercle in the 

 child ; whilst, on the other hand, the tubercle bacilli 

 usually associated with pulmonary tuberculosis in the 

 adult human subject being of the human type, have 

 probably passed through a number of men and women, 

 one transmitting it to the other in direct succession. 



During the few days that have elapsed since the 

 appearance of the Report some criticism has been 

 directed against it on the ground that all the moot 

 questions concerning tuberculosis have not been 

 answered. This is surely unreasonable, as it cannot 

 lie too clearly recognised that the reference to the 

 Commissioners was exceedingly closelv defined. Thev 

 had no authority or power to go beyond this reference. 

 Indeed, the time — ten years — required for the elucida- 

 tion of the special questions referred to them gives a 

 definite indication of the propriety of the limitations 

 imposed upon and accepted by the Commission. 



Many and most important questions bearing on 

 the cause and cure of tuberculosis have still to be 

 answered. This can be done only by well-trained 

 men working on an organised plan, co-operating 

 whole-heartedly for a considerable period, and well 

 supplied with financial means, facilities, accommoda- 

 tion, and equipment. That some organised scheme of 

 work will be devised can now scarcelj he doubted, and 

 ii is to be hoped that it will be adequately supported 

 by Government. Such legislation has long been under 

 consideration, and it mav be that it has been held back 

 until the appearance of this Report. Now, bis dat 

 qui . ito dat. 



Although the Commissioners make no direel recom- 

 mendation as to legislation, anyone who reads their 

 Report can have- little doubt as to their opinion on 

 this matter, ami we feel satisfied that those in high 

 places will realise that in bringing forward such legis- 

 lation as may tie necessary to ensure a pure milk 

 supply, their hands are greatly strengthened by the 

 findings hei e recorded. 



The Commissioners were evidently splendidly served 

 by tin Secretan and by their staff of scientific 

 assistants, as the\ insist very strongly on the value 

 of the services rendered by these gentlemen in the 

 carrying out of the scheme of work planned at the 

 outset. 



In conclusion, it mav be pointed out that one name 

 not hitherto mentioned in connection with the forma- 

 tion of this Commission is that of Sir Herbert Max- 

 well, who, during the Congress and until the com- 

 pletion of the arrangements for the Commission, 

 planned carefully and worked indefatigably to get 

 together a thoroughly representative Commission. 



