The Gkowtii of thk Nativk Hacks op Capk Colony. 261 



the natives — especially since the Anglo-Boer war—is enteric fever. 

 It is likely to persist, and probably to increase, but there is no reason 

 to apprehend its having any material effect on the growth of the 

 pojxdation. 



From our jiresent point of view the disease whicli is of para- 

 mount iuiportance is tuberculosis ; circumstances strongly point to the 

 tubercle bacillus proving to be the deadliest enemy with which the 

 native races of this country have ever been brought face to face. 

 Among the natives in the colony proper and in inany native areas its 

 ravages are already terrible, and the process of spread seems to 

 be only beginning. In Clarkson mission station, out of 86 deaths 

 of persons over fifteen since 1897, 52 were due to tuberculosis; for 

 Enon mission station, since 1895, the corresponding figures are 

 104 and 55. Largely as a rc^sult of the prevalence of this disease, 

 and after making allowances for migration, the population of Clarkson 

 is at present stati<mary; that of En<m is actually dwindling. In other 

 mission stations tuberculosis causes well over 33 per cent, of the total 

 deaths of adults In the sixty chief towns of the colony the native 

 mortality rate from tuberculosis in 1904 and 1905 was over 6-5 per 

 1000 per annum. The average native exposed to the infection of 

 tuberculosis seems to pick it up as a sponge does water ; the disease 

 in a ver}'^ large proportion of cases is of an acute type — acute infiltrat- 

 ing phthisis or miliary tubei'culosis — and it is almost invariably fatal. 

 The labour centres play a very important part in its dissemination. 

 Here a native fi-equently sleeps in a dormitory with a number of 

 others, some of whom have phthisis ; he contracts the disease, works 

 until he becomes too weak, and then returns to the paternal kraal, 

 where he dies, usually after a few months, during which period he has 

 infected other members of the famih'. The liabit of expectoration 

 anywhere and evexywhere, almost universal among the natives, the use 

 of clothing, blankets and eating utensils in common, the structure of 

 the hut with its earth floor and walls and absence of sunlight and 

 ventilation, all combine to strongly favour the rapid spread of the 

 disease. Whole families are not infrequently wiped out within a 

 comparatively short period, and even in many remotely situated native 

 areas the process is now rapidly going on. Why, it niay be asked, 

 in this country with its dry sunny climate, which exercises such a 

 favourable influence on cases of phthisis from Europe and in which the 

 disease is comparati\'ely uncommon and runs a protracted course, often 

 ending in recovery, in Europeans, should the disease exhibit such 

 extraordinary virulence in the native races 1 No doubt the avei'age 

 European environment is much less favourable to its spread, but this 

 only accounts for a small part of the difference ; there can be no doubt 

 that the chief factor is a greater susceptibility to the disease on the 

 part of the native races. We must look to the operation of the 

 principle of natural selection for an explanation. 



Broadly speaking, the resistance of a race to an infectious disease 

 varies in direct proportion to its past experience of that disease. The 

 history of primitive races furnishes many illustrations of the working 



