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come to light only under definite conditions, and at some 

 particular point of her or his development, and this par- 

 ticular moment corresponding with a similar moment in the 

 progenitors. Hereditary diseases are, in fact, good instances 

 of heredity at corresponding periods. Thus chorea, which 

 usually makes its appearance in childhood, chlorosis in 

 youth, consumption in middle age, gout in old age, are 

 naturally hereditary at the same periods. With regard to 

 the inherited tendency to chlorosis, the disease is often 

 found breaking out in the majority of, or in all, the female 

 members of a family from one generation to another, oft 

 repeated, and at corresponding periods of life, and this inde- 

 pendent of the external circumstances amid which they may 

 have been brought up. Previous to the development of the 

 chlorotic attack, predisposed girls have usually manifested 

 anaemia, and functional irritability of the nervous system, 

 but not invariably, as the attacks have been known to occur 

 unexpectedly in seemingly robust and healthy girls. In 

 whatever way produced, however, and under whatever 

 circumstances, there is in the generality of, if not in all 

 cases, a predisposition which is potently and emphatically 

 hereditary. 



Progressive Pernicious Ancemta. I only allude to this rare 

 .and mysterious affection in order to make the list of affec- 

 tions now under discussion as complete as possible. 

 Unfortunately, so little is known as to the etiology or 

 pathology of this morbid condition that I am unable to 

 furnish any evidence as to whether it can be said to be 

 hereditary or not. Closely allied in kind to ordinary idio- 

 pathic or symptomatic anaemia and severe chlorosis, it yet 

 differs materially from either in degree, and is characterised 

 by the so-called " anaemic fever " of Biermer, which, 



