290 GENERAL ANATOMY. 



that we ought to attribute this remarkable phenomenon, to the 

 more or less multiplied internal ruptures that the artery ex- 

 periences before its total division at any one point. The phe- 

 nomena which follow are the same as after the transversal 

 section. (428.) 



430. A ligature applied to an artery, either when entire, 

 or when it is cut as at the surface of an amputated limb, suffi- 

 ciently tight to arrest the circulation in the vessel, cuts the in- 

 ner and middle membrane,and,if the artery is healthy, without, 

 divides the outer one. If the ligature is permitted to remain, 

 the blood stopped in the vessel coagulates in its cavity as far 

 as to the nearest branch. The division experienced by the in- 

 ner membranes, the pressure exercised on the external ones and 

 the presence of the ligature, induce an effusion of organizable 

 matter, which produces at first the agglutination of all the in- 

 jured parts; the part embraced within the ligature is at first 

 softened, is afterwards divided by the effect of inflammation, 

 and the ligature comes off. The changes which follow in the 

 vessel are the same as after the transverse section. (428.) 



431. In the three kinds of wounds of which we have just 

 treated, (428, 430.) the ulterior phenomena are different, ac- 

 cording as they are made on an amputated surface or in the 

 continuity of the parts. In an amputated surface, the princi- 

 pal artery is not only obliterated, but also its branches termi- 

 nating at the surface, so that the trunk itself is more or less 

 narrowed. In the other case, on the contrary, the branches 

 which arise from the artery on which a ligature has been ap- 

 plied, divided or torn, not only continue to carry on the cir- 

 culation, but dilate in order to supply the principal trunk; 

 they thus keep up, even to the point where they arise, the 

 fluidity of the blood, its motion, and its influence on the vessel. 

 It is to this difference that must be ascribed the frequency of 

 the primitive reunion of divided arteries on an amputated sur- 

 face, and the comparative few cases of this happy result, when 

 the division of the artery happens in the soft parts. 



432. We sometimes find a cartilaginous production or 

 transformation, with thickening of the parietes of the arteries, 

 commonly in a somewhat confined extent. Athcromatous, 



