414 THE HEMORRHAGIC DIATHESES 



ferentiation of hemophilia from related clinical pictures which are included ii 

 the conception of the hemorrhagic diathesis, i. e., from scurvy and morbui 

 maculosus Werlhofii. The former differs from hemophilia decidedly by th< 

 fact that it is rarely sporadic, but usually endemic or epidemic. Still mor( 

 characteristic, however, is its dependence upon external conditions; it is thi 

 expression of severe disturbance of nutrition produced by obscure diseases o] 

 by long-continued insufRcient and improper nourishment. Morbus maculosus 

 Werlhofii differs from hemophilia particularly in that it unquestionably belongs 

 to the acquired diseases, in which the factor of heredity plays no part. This 

 affection is never congenital as is the case with hemophilia, and this differentia] 

 peculiarity also applies to scurvy. Unlike the scurvy patient, the bleeder is fre- 

 quently well nourished and strong, and except for his tendency to spontaneous 

 hemorrhages he might almost be considered healthy. 



In comparing hemophilia with related diseases in the group of the hemor- 

 rhagic diatheses, one peculiarity of hemophilia stands out prominently. Id 

 contrast with what is found in the diseases previously named, it is not a 

 pathologic process but a permanent condition which manifests itself sometimes 

 after recognizable causes (traumatic hemorrhages), at other times following 

 unknown ones (spontaneous hemorrhages). For this reason hemophilia has 

 been designated as a " vitium primse formationis." 



Hemophilia is probably in all cases a congenital, and also a hereditary con- 

 dition. The intensely hereditary character of this pathologic condition has 

 been from the earliest times a source of great interest. Grandidier calls it 

 " the most hereditary of all hereditary diseases." Only very exceptionally is 

 a single case of hemophilia observed in a family. The most striking point is 

 the frequency of the cases in one and the same family. From a study of the 

 total number of known hemophilia cases and their distribution in individual 

 families, it may be noted that in every family of bleeders there are at least 

 three bleeders. Sometimes the transmission is immediate from the parents 

 to the child. Much more frequently, however, the transmission of the disease 

 follows a peculiar law of heredity, peculiar because it reveals a remarkable 

 sex difference in the frequency with which hemophilia is acquired and trans- 

 mitted. Females show a greater tendency to transmit the disease; while, 

 in contrast to this, in the male sex a predisposition to acquire the disease is 

 prominent. The latter predisposition is evident from the fact that the major- 

 ity of bleeders are of the male sex. The tendency of the female to transmit 

 hemophilia is characterized by another peculiarity. A woman from a bleeder 

 family may transmit hemophilia to her offspring without herself being hemo- 

 philic, the disease skipping a generation. This order of transmission is indeed 

 the rule. Formerly, when fewer reports of cases were at hand, it was believed 

 that only males were affected by the disease, females being exempt, and that 

 it was women exclusively who transmitted the disease. On this assumption 

 first the laity and subsequently also scientists designated the women in families 

 of bleeders as "conductors." Close investigation and increasing experience 

 have, however, taught us that females also may be attacked by hemophilia, 

 although far less frequently than males. For every thirteen males there is 

 one female bleeder. The view that women exclusively transmit the disease 



