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frequently is this the case ! And there cannot be a shadow 

 of a doubt that whether we regard "the average power of 

 renewing the constituents of the blood, the average rapidity 

 with which they are utilised in nutrition and growth, and 

 finally, the average amount of the blood store (as the 

 resultant of the first two elements)," they are singly and 

 collectively subject to the influence of heredity. The 

 exciting causes of anaemia are numerous and important : 

 but whether we regard the affection itself in its physiological 

 or pathological aspect, we find in one as in the other almost 

 invariably a predisposition which is inherited more or less, 

 in differing degrees, and that the physiological predisposition 

 will very readily become developed into the pathological. 



Chlorosis. To the influence of certain predisposing 

 causes inherent in the patient's constitution we must trace 

 the source of chlorosis ; and these are principally sex, 

 age, and heredity, which have the greatest share in its 

 development. Sex and age are, in this affection, of pre- 

 eminent importance, inasmuch as no combination of causes 

 from which these are omitted are competent to develop it. 

 In fact, youth and the female sex are indispensably necessary. 

 With regard to age, chlorosis usually affects young girls 

 between the ages of fourteen and twenty-four, during the 

 time when sexual evolution occurs. Of no less importance, 

 however, is the influence of heredity, as an inherited pre- 

 disposition must be admitted to exist in many, if not the 

 majority of cases. Moreover, the heredity of chlorosis may 

 be taken as an example of certain inherited affections which 

 usually manifest themselves at the same period of life at 

 which they affected parents or ancestors, and which have 

 been explained on the hypothesis of latent characteristics 

 contained in the individual in the germ state, and which 



