430 DISEASES OF THE GREAT VESSELS. 



behind the peritonaeum. Inflammation of the pulmonary veins, termi- 

 nating in abscess, is equally rare. 



Dilatation of the great venous trunks takes place in diseases of the 

 heart, which occasion engorgement of the venous system. Their con- 

 striction is almost solely the result of compression by adjacent tumors. 



Primary thrombosis that is, coagulation of the contents of a vein, 

 with consequent inflammation of its walls has been seen occasionally 

 in the vena cava ascendens, but then the coagulum almost always forms 

 first in one of the femoral veins, and afterward spreads to the vena 

 cava. Such a formation of thrombus may be recognized by the follow- 

 ing signs : If, in addition to the tense painful oedema of a phlegmasia 

 alba dolens of the leg, there suddenly set in a painful swelling of the 

 other limb, if the secretion of urine be suddenly repressed, or should 

 it become scanty and bloody, we may infer that the thrombus has in- 

 volved the vena cava and emulgent veins. 



ADDITION TO THE REVISED EDITION OF 1880. 



SECTION III. DISEASES OF THE GREAT VESSELS. 



1. P. 415. 



Traube has recently raised doubts as to whether this thickening 

 of the arterial wall (arteriosclerosis) is always attributable to in- 

 flammation, and supposes that the process may depend rather upon 

 an emigration of white blood-cells into the intima. As a first step 

 there is a retardation of the blood-current. This allows opportunity 

 to the lymph-bodies of the blood to accumulate in the peripheral 

 parts of the current and to adhere to the inner surface of the vessel. 

 The mass gradually increases, and they migrate through the epithe- 

 lial layers, and only stop when the canal system through the intima 

 ceases to afford them passage. Once at rest, the corpuscles turn 

 into spindle-form and star-shaped cells, and so forth. 



