298 iJlSTURBAyvE.S OF CIRCULATION 



neonatorum exhibits decreased prothrombiu in tlie blood, while in 

 leukemias and anemias there may be an excess of antithrombin,-"'' 

 leading to severe hemorrhage (see also Thrombosis). 



Since hemophilia seems, superficially at least, to depend upon some 

 alteration in a chemical property of the blood, namely, coagulability, 

 it is frequently i-egarded as an example of hereditary transmission 

 of a chemical abnormality. The exact cause of this peculiar tendency 

 to prolonged bleeding from insignificant or perhaps imperceptible 

 wounds has been sought vigorously by both histological and chemical 

 means, but as yet without avail. Various observers have described 

 abnormal thinness, or increased cellularity or fatty degeneration of 

 the vessel-walls, but the findings have been far too inconstant to 

 afford a satisfactory anatomical explanation of all the features of 

 hemophilia. Likewise increased blood pressure can be ruled out, for 

 although the left heart is frequently enlarged, there is usually no in- 

 creased blood pressure demonstrable; furthermore, conditions of 

 high blood pressure, such as nephritis, do not cause hemophilia. The 

 theory of "hydremic plethora" is also without good foundation. 



The most natural place to look for the fundamental fault is in the 

 blood, but speaking strongly against this is the occasional occurrence 

 of "local" hemophilia; e. g., in this type of hemophilia wounds of the 

 skin may behave as in normal individuals, whereas any injury of the 

 mucous surfaces is followed by pronounced hemophilic bleeding ; - ' 

 in other cases the hemophilic bleeding is limited to regions above the 

 shoulders; in still another class the bleeding is always from one or- 

 gan, e. g., the kidney's. Nevertheless, a great deal of investigation of 

 the blood has been done, at first chiefly with negative results. There 

 are no characteristic changes in the cellular elements of the blood, 

 beyond the changes common to all secondary anemias, excepting pos- 

 sibly a decrease in the number of white corpuscles with a relative 

 increase in the number of lymphocytes as observed hy Sahli; the 

 platelet count is normal. No constant alterations in the salts of the 

 blood have been found, calcium usually being normal ; and the propor- 

 tion of water, fibrinogen and the several other proteins, the alkalinity, 

 and the osmotic pressure of the serum all seem to be normal. IMetab- 

 olism is unchanged, except possibly for calcium loss in some cases.-* 

 Since bleeding is normally stopped principally by coagulation, a de- 

 ficiency in fibrin oi' its antecedents might be expected, but most 

 studies on this point have shown a noi-mal amount of fibrinogen in 

 the blood of hemophilics, the fre(pient formation of large tumors of 

 clotted blood at the bleeding points supporting the experimental 

 evidence that the blood contains an abundance of fibrinogen. The 



2od Whipple, Arcli. Int. Aled., 1913 (12), 637. 

 27 Ahdi'ilialdcii, Zicfrl,.,'s I'.oiir., 1!)04 ( .T) ) . '213. 



2« Kulin, Amer. Jour. Dis. Cliildroii, lOKJ ( 11 ), 103: Laws and Cowie, ibid., 1917 

 (13), 236; Hess, Bull. Joiins Hopkins Hosp., 1916 (26), 372. 



