July 27, 1911] 



NATURE 



d. The combination of the results arrived at by 



pical investigation and experimental study appears 



need tor further discussion. A long step 



■S thus been taken in defining the direction in which the 



instigation of cancer is alone likely to be profit- 



abli . 



The Nature of Cancer. 



It follows from the argument pursued in the preceding 

 phs that a closer definition of the nature of cancer 

 will involve an analysis of the relation obtaining between 

 the individual developing cancer and the tumour. 



In all previous reports guarded reference has been made 

 to tin mediate relation obtaining between chronic irritation 

 ;'[)<! certain forms oi cancer. The indefiniteness in the 

 way of directing attention to the relationship has been 

 In the first place, it is due to an effort to 

 lorms of cancer with which irritation is 

 most constantly associated without considering other forms 

 in which the particular irritants concerned do not play a 

 part. In the second place, it is due to the fact, already 

 Rquently emphasised, that these irritants have nothing in 

 common beyond their association with cancer. The varied 

 investigations of the past nine years have added a know- 

 Kge of new forms of irritation. It has become more and 

 more evident that irritation, effective in one case, may be, 

 and often is, quite ineffective in another. 



It has been ascertained that every fresh transplantation 

 effects a disturbance of the cancer cells. They are thrown 

 into a state equivalent to regeneration from which they 

 tend to recover, as analogous as possible to reactive 

 proliferation when naturally occurring. 



Ever since the beginning of these investigations it has 

 been maintained that the mere cultivation of cancer had 

 important, if only indirect, bearings upon its nature and 

 genesis. Thirty-five of the tumour-strains have now been 

 ■rowing for more than three years, i.e. for longer than a 

 Bouse lives, while fifty other strains have been grown for 

 Etended periods. The one feature all these tumour-strains 

 hav. 1 common is the power of continuous growth which 

 they possess, in spite of the most divergent structure, and 

 of extremes in the rate of growth varying from an almost 

 explosive rapidity to one much inferior to that of embryonic 

 tissue, as determined by weighing experiments. 



It can be shown that there is a constancy in the 

 behaviour of a tumour-strain and a variability which is 

 individual. The variations which occur are similar to 

 those which distinguish the eighty-five different strains 

 from one another. They are not mainly induced by the 

 environment, but arise spontaneously; otherwise all strains 

 would approach a common type, which they do not. The 

 demonstration of the occurrence of these variations under 

 artificial conditions permits of the inference that they could 

 also occur under natural conditions, and yields objective 

 Evidence of the validity of the conclusion that the cancer- 

 cell is a biological modification of the normal cell endowed 

 witii many inherent properties of the latter. The objection 

 at once suggests itself that these variations during pro- 

 longed propagation are secondary, and do not necessarily 

 indicate corresponding primary changes as responsible for 

 genesis; but this objection cannot be maintained against 

 the facts that the potentiality for variation has been demon- 

 strated, as has also the tenacity with which the several 

 varieties are adhered to. 



Immunity and Therapeutic Investigations. 



"I he dissemination of cancer has been studied experi- 

 mentally both by injecting cancer-cells directly into the 

 blood-stream and by implanting them in internal organs. 

 It has been found possible to produce the lesions of dis- 

 semination in these ways both in the absence and in the 

 presence of a primary growth, and what is more important 

 also, to prevent them. Problems difficult of solution in 

 the mouse, because of its small size and the short duration 

 of iis life, can now be studied in the more favourable 

 circumstances obtaining in the rabbit, the extension of 

 experiments to this animal being a new feature made 

 possible by the successful propagation of a sarcoma from 

 rabbit to rabbit. 



_ Nothing but harm can result from the premature applica- 

 tion 10 the treatment of the human subject of methods 

 found to modify the growth of propagated cancer in 

 animals. The methods which induce an active immunity 



NO. 2178, VOL. 87] 



to propagated cancer have been tested on thirty-three mice 

 with natural cancer, and have given no evidence of powers 

 either to hinder growth and dissemination or to prevent 

 recurrence of spontaneous cancer after surgical removal. 



The successful treatment of animals bearing propagated 

 cancer by means employed to induce passive immunity lias 

 been described by other investigators. Some of these 

 methods have been tested in the laboratory, but have not 

 yielded positive results. It becomes increasingly evident 

 that the therapeutical treatment of cancer is not to be 

 sought for along these lines. 



A considerable number of cases of natural healing of 

 spontaneous malignant new growths have now- 

 observed in mice affected with spontaneous cancer. The 

 changes leading to natural cure appear to depend, as in 

 propagated cancer, on an altered condition of the cell and 

 its contents rather than on an alteration in the general 

 condition or constitution of the affected animal. Mi ans 

 must be devised for elucidating the nature of the change 

 in the cell before curative measures can be discovered. 



Since these investigations were first contemplated by 

 those responsible for their inauguration, the provisions 

 made for the investigation of cancer have greatly allied 

 in this country. Whereas nine years ago, apart from 

 special provision for treatment being supplied by a numbi r 

 of hospitals, there existed for the investigation of the 

 disease only one other laboratory in addition to the 

 Imperial organisation contemplated by the founders of this 

 fund. To-day a number of other laboratories exist 

 throughout the country, both in London and the provinces. 

 England and Scotland are now provided with a greater 

 number than any other country in comparison with their 

 size and population. Whenever an opportunity has 

 occurred of furthering the particular investigations upon 

 which these institutions have been engaged, assistance has 

 been rendered by supplying material from the laboratory 

 and by the Imperial Cancer Research Fund in many other 

 ways. The responsibilities thrown upon the workers of 

 the Imperial Cancer Research Fund are not diminished, 

 but rather increased, by the multiplication of institutions 

 engaged in the investigation of cancer. 



THE BOARD OF EDUCATION'S SCIENCE 



EXAMINATIONS AND GROUPED COURSE 

 CERTIFICATES. 1 

 A S is well known, the Board of Education for some time 

 past has been considering the reorganisation of the 

 existing system of science examinations conducted by the 

 Board, in the hope of lessening the somewhat heavy cost 

 of these examinations and of securing greater educational 

 efficiency. The conclusions arrived at by the Board have 

 recently been published in a circular, accompanied by a 

 covering letter from Sir Robert Morant, in which is 

 summarised the principal changes which the Board has 

 decided to bring into operation in the session 1911-12. 



The general principles governing the action of the Board 

 in respect to the proposed alterations are given in the 

 following extract from Sir Robert Morant's letter : — 



" The examinations were instituted in circumstances 

 widely different from those of the present, at a time when 

 no other machinery for promoting scientific or technical 

 instruction was generally available ; and they have in the 

 past contributed greatly to the diffusion of scientific and 

 technical knowledge throughout the country. But during 

 recent years there has been a great development in the 

 teaching of the subjects covered by the examinations in 

 evening and technical schools, the organisation of which is 

 uily affected by the nature of the examination tests 

 available ; and the Board have had to consider under what 

 conditions a system of science examinations, conducted not 

 by the teachers of the schools but by an external body, has 

 .1 !-. claim to continued existence, and how the working of 

 the system so far as it is retained can best be coordinated 

 with and made to supplement the work of the teaching 

 institutions themselves." 



It is evident that the Board recognises the very great 

 difference between the general educational conditions in 



1 '- Science Examination and Grouped Course Certificates." Board of 

 Education Ocular, No. 776, June 20. 



