288 GENERAL ANATOMY. 



the parietes, and internally a plastic exudation, sometimes pus, 

 and at others more or less extensive ulcerations. 



427. The wounds* of the arteries present anatomical con- 

 siderations of great importance. The puncture of an artery 

 gives rise to a feeble hemorrhage if the vessel be surrounded 

 by cellular tissue; but it is greater if it be deprived of its 

 sheath. The hemorrhage is arrested by the coagulation of the 

 blood, which is afterwards gradually absorbed; there is, during 

 a short time, a small enlargement opposite the puncture; after- 

 wards so very perfect a cicatrix is formed, that it is impossi- 

 ble to perceive it. A small incision, lengthwise with the 

 vessel, opens a little, and gives rise to a hemorrhage greater 

 than that produced by the puncture. The cure is sometimes 

 effectuated afterwards, and in the same manner. A transverse 

 incision produces, by the considerable separation of its edges, 

 a more or less serious hemorrhage, according to the extent 

 of the laceration of its cellular sheath. The hemorrhage is 

 the more serious, the more the incision involves, more than 

 one half of the circumference of the vessel, a case in which, if 

 left to itself, it continues or is renewed after being stopped, 

 until death takes place. In the cases in which the lesion reaches 

 only a small part of the circumference, if the sheath exists, 

 after having bled more or less, the blood infiltrates and coagu- 

 lates in it, and sometimes a cicatrix is formed, which, in man, 

 is much less solid than the original parietes of the artery, and 

 which becomes commonly the seat or the cause of a consecu- 

 tive aneurism. When, on the contrary, the transversal divi- 

 sion is much greater than one half of the circumference, the 

 retraction, as well as the diminution of its size, which result 

 from it, is such, that if the sheath still exists, the blood infil- 

 trates, stops, and coagulates in it, and the cure may also take 

 place. But in order that this may occur, the complete divi- 

 sion of the artery is accomplished, and then this case belongs 

 to the following. 



428. Whenever an artery of a mean caliber is cut across, 



* J. F. D. Jones, on the process employed by nature in suppressing hem- 

 orrhage, 6fc. Lond. 1810. Beclard, loc. cit. 



