BY EUGEN HIRSCHFELD, M.D. 71 



to a certain extent a constant, if an insufficient, weeding out 

 from the candidates for matrimony of those who are most 

 seriously liable to this disease ; but in the case of cancer there 

 will be no such preservative influence, and so long as persons with 

 this inherited tendency marry practically without let or hind- 

 rance of any kind, there must be a constantly growing proportion 

 of the population that shares in the constitutional defect." But 

 though there is no doubt that this argument explains increase ©f 

 cancer to a small extent it is quite insul^icient as a reason for 

 this enormous increase (seven times as much in the male popu- 

 lation and treble for the whole of it), within the comparatively 

 short space of thirty years. 



We are, therefore, forced to the conclusion tliat the rapidly 

 and greatly increasing prevalence of cancer in the Australian 

 colonies cannot be accounted for by an increase out of proportion 

 of that part of the population which is most liable to malignant 

 tumours (aged persons), nor by greater accuracy of diagnosis 

 even by a certain small natural increase in consequence of heredi- 

 tary transmission ; that on the contrary the improved diagnosis 

 of the earlier stages, together with the advancement of surgical 

 treatment, should warrant a diminution instead of an augmen- 

 tation of the cases of death caused by cancer. 



You will have noticed that so far I have pursued the rather 

 unusual course of stating the reasons that were not responsible 

 for the increase in the death rate from cancer. But this course 

 was absolutely necessary in this case. As regards cancer we are 

 not in the same satisfactory position, as for instance in phthisis, 

 where our knowledge about the causation of the disease is per- 

 fectly exact. The aetiology of cancer is still obscure, and it is 

 not advisable, by hastily jumping to conclusions, to bring for- 

 ward reasons for the increase of cancer in this country. After 

 having the whole material sifted I shall be in a better position 

 to do this, especially as soon as the influence of localisation, 

 age, sex, climate, race, seasons, years, &c., has been investi- 

 gated, as I intend to do in my next paper. 



The next point I wish to draw your attention to to-night is 

 the greater prevalence of malignant tumours amongst the female 

 part of the population compared with the males. As you see 



