REPAUATORY IN'FLAMMATIOX IX ARTERIES. 25 



eiiery blood-clot presented the most unmistakable appearance 

 of lamination or stratification. This feature was uniformlj' 

 present througiiout the whole of the first series, as well as 

 throughout all of the others. It may be stated, however, that 

 some of the transverse sections did not present this appearance 

 of lamination. Fig. 2, although drawn under a low power 

 from a preparation of fort3'-eight hours, fairly represents the 

 stratified appearance of all these blood-clots when seen upon 

 section in profile. 



In order as much as possible to avoid repetition, the further 

 discussion of the constitution of the blood or filn-inous clot will 

 be deferred until we consider the structure of that of forty-eight 

 hours. 



Eecurring once mere to the plastic or cellular clot of 

 twenty-four hours, running through the accumulation of 

 colorless cells at the bottom of the vessel are to be found 

 narrow, highly refractory bands, evidently portions of the 

 elastic laj'er of the split and lacerated tunica intima. Dissocia- 

 tion of the plastic clot with needles shows the great majority 

 of the cells constituting it to be flat, swollen, granular, and gener- 

 ally oval, with ordinarily one moderately large and round or 

 slightly oval granular nucleus. Sometimes these cells contain 

 a large nucleus with a constriction in the middle; sometimes 

 two or more smaller nuclei ; occasionally the body of the cell 

 itself shows a tendenc}^ to the same constriction. They often 

 possess a transverse diameter twice as large as that of the 

 white blood-corpuscle, and a longitudinal diameter sometimes 

 three and occasionally even four times as great as the latter. 

 The general arrangement of these cells seems to have special 

 relation to the plane of the elastic layer of the Lunica intima, 

 whether this layer occupy its accustomed position relative to 

 the media, or whether it be found scattered through the cellu- 

 lar accumulation in the shape of the previously mentioned 

 bands. While the disposition of these cells evidently is to 



