CHANGES IN THE CIRCULATION OF THE BLOOD. 71 



HEMORRHAGES IN THE NEW-BORN. 



Haemorrhages, sometimes extensive, in various parts of the body 

 gastro- intestinal canal, mouth, nose, navel, or the viscera are not infre- 

 quent in the first few days of life. Aside from the occasional discovery 

 of ulcers in the gastrointestinal walls, the reason for these haemorrhages 

 is not evident at autopsy. This condition has been called morbus macu- 

 losus neonatorum. Haemorrhages from the skin, mucous membranes, or 

 navel may take place in the syphilitic new-born. Haemoglobinuria may 

 occur in epidemic form in young children. 



HEMOPHILIA (Hcemorrhagic Diathesis'). 



This abnormal condition consists in a liability to persistent haemor- 

 rhage on the slightest provocation, and is dependent upon some consti- 

 tutional peculiarity which is unknown to us. It is usually hereditary. 

 An uncommon thinness of the intima of the arteries has been noticed in 

 some cases, and other changes have been described ; but there are no con- 

 stant lesions associated with the haemorrhages, as yet discovered, which 

 would satisfactorily account for their occurrence. The haemorrhages may 

 be traumatic in origin, or they may occur spontaneously from the mu- 

 cous membranes. 



TRANSUDATTON. 



Transudation is the passage, through the walls of the blood-vessels 

 into the interstitial spaces outside, of fluid from the blood, with little or 

 no admixture of its cellular elements. This occurs constantly, to a cer- 

 tain extent, under normal conditions, and forms the commencement of 

 the lymph circulation. But when the amount of fluid passing through 

 the walls of the blood-vessels is increased, or its outflow into the larger 

 lymph trunks is hindered so that it accumulates in undue quantity in the 

 interstices and lymph channels of the tissues, the condition is pathologi- 

 cal. An accumulation of transuded fluid in the interstices of the tissues 

 is called oedema ; in the serous cavities, dropsy. 



Its occurrence may depend upon some hindrance to the venous circu- 

 lation or increase of capillary pressure, especially when associated with 

 alterations in the walls of the blood-vessels or upon changes in osmotic 

 pressure induced by a reduction in the nutrient efficiency of the blood, 

 by injuries, or in other ways which may affect the processes of filtration 

 and osmosis, by which chiefly, it is believed, the normal transudation of 

 fluids occurs. There is, furthermore, strong and increasing evidence that 

 the eudothelial cells of the capillaries possess active secretory or other 

 functional capacities which should be taken account of in the attempt to 

 comprehend transudation as well as many other pathological phenomena 

 and lesions. A simple interference with the outflow of lymph does not 



1 For a study of lymph formation see Hamburger, Ziegler's " Beitrage zur path. 

 Anat.," Bd. 14, p 443, 1893, for oedema see Meltzer, Harrington Lectures, Univ. of 

 Buffalo, 1904. 



