HEMOPHILIA 423 



The abnormal composition of the vascular system is said to consist in the 

 greater tendency of the vascular walls to rupture, and this has been thought 

 to be due to a peculiar thinness and narrowness of the arteries, as well as to 

 their very superficial situation. Even were this condition more common than 

 is actually the case, these vascular alterations would not sufficiently explain 

 the spontaneous hemorrhages, for we find similar changes in the narrowed 

 aorta of chlorosis but no hemorrhages. In discussing the pathological anatomy 

 we shall revert to this ; at present it need only he stated that some investigators 

 such as Hooper, Listen, Fischer and others found the walls of the arteries 

 in hemophilia very thin and showing fatty degeneration. Virchow laid 

 special stress upon the fact that in a bleeder, aged twenty-four, the aorta was 

 not only very thin and elastic but also very narrow, almost of infantile dimen- 

 sions, while the capillary vessels showed no change. Elastic arteries which 

 are too narrow propel the blood into the capillaries with too great force, and 

 this circumstance favors the hemorrhagic diathesis, or at least the continuance 

 of the bleeding. This narrowing of the arteries cannot be ascribed to any 

 special disease of the walls of the vessel, but to a disturbance of development, 

 analogous to the condition in chlorosis; this is consistent with another special 

 characteristic of hemophilia, namely, the marked hereditary tendency of the 

 affection. AVhether the fatty degeneration of the intima, which has been found 

 in some cases biit by no means in all, is not rather the result of the post- 

 hemorrhagic anemia than the cause of hemophilia is also questionable. At 

 the autopsy of some cases of hemophilia, hypertrophy of the left ventricle 

 with extreme thinness of the right has been found, and this circumstance has 

 been suggested as an explanation of the hemorrhages. If the blood be pro- 

 pelled with great force through the narrow, thin-walled arteries, the increased 

 pressure of the hypertrophied left ventricle may cause a rupture. Apart from 

 the comparative rarity of hypertrophy of the left ventricle, it must be remem- 

 bered that a great number of the hemorrhages are of a diapedetic nature, and 

 cannot be referred to rupture of the vessels alone; besides, we note the same 

 symptom-complex in congenital narrowing of the aorta without the sequence 

 of extensive hemorrhages such as frequently recur in hemophilia ! 



The fallacy of these mechanical explanations became more evident as opin- 

 ions multiplied that an insufficient coagulability of the Mood was the cause. 

 The latter conclusion concerning the blood was the result of experience that 

 in hemophilia all hemorrhages, even with the most insignificant beginning, 

 are difficult to control. The blood does coagulate, however, as may be seen 

 from the surface of wounds; spontaneously it forms coagulated masses from 

 beneath which new quantities of blood exude, and these also soon coagulate, 

 and thus enlarge the blood clot. Gradually the oozing of blood ceases, and 

 the hemorrhage is arrested. Sometimes, however, in more severe hemorrhages, 

 there is complete cessation of the production of the fibrin ferment, the blood 

 gradually loses its power of coagulation, the hemorrhages progressively drain 

 the tissues, and death results from excessive loss of blood. Any form of 

 hemorrhage may be fatal, but this is most frequent in epistaxis; next, after 

 extraction of teeth ; and, occasionally, in intestinal hemorrhages, etc. 



Microscopic and chemical examination of the blood has shown normal 



