36 THE TOXEU LECTURES. 



clot was not to be seen, and no trace of any tendenc}^ to or- 

 ganization of the blood-clot could be made out. In the plastic 

 clot only slight traces of the previously mentioned elastic bands 

 from the intima could be observed. Yet the elastic layer 

 of the intima where its relation to the media had been undis- 

 turbed by violence was sharply defined and not much changed. 

 Neither had the protoplasm in the media immediately beneath 

 suffered much visible increase. The cellular infiltration of the 

 adventitia and media near the ligature had materially advanced 

 — a still further preparation for the separation of the thread. 



Fig. 5. A faithful representation of a highly magnified view 

 of a transverse section of a thrombosed femoral arter}^ of a 

 dog, ninety-four hours after ligature. The section passed 

 through the middle of the plastic clot. An attempt to loosen 

 the thrombus from its attachment to the arterial wall had been 

 successfully made, thus performing without the aid of needles 

 a dissociation of the cells which were next the intima. a. Ad- 

 ventitia. m. Media, e. Elastic folds of intima perfectl}' defined, 

 and showing as yet not much if any tendency toward breaking 

 down. p. Oval- and lozenge-shape cells of the plastic portion 

 of the thrombus, their outlines, processes, and nuclei being well 

 seen. 



The next stage of the healing process was made out from 

 the examination of four preparations, viz. : two arteries at 

 eight days, and two at ten days after ligature. The general 

 result may be stated thus : In some cases, granulations spring- 

 ing from the plastic clot have penetrated nearly every crack 

 and crevice of the blood-clot. In these cases the blood coagu- 

 lum has formed early and firm attachments to the vessel-wall. 

 It consequently occupies a height above the point of ligation 

 nearly identical with that which it occupied at its first forma- 

 tion, the increase of the plastic formation finding vent in the 

 honeycombing of the blood-clot rather than by uplifting the 

 latter. In other cases the growth of the plastic clot finds the 



