REPAUATOKY INFLAMMATION IN ARTERIES. 35 



while the highest was the smallest stratum. Not the slightest 

 sign of a tendency to organization was recognizable here. 



Fig. 2 represents a longitudinal section of a 48-hour thrombus 

 in the femoral artery of a dog, low power. 



a. Adventitia. m. Media, p. Plastic clot. e. Intima. d. 

 Blood-clot, three lower laminated portions. /, Apex of blood- 

 clot — different in structure from the three lower portions, g. 

 Bands of fibrin uniting the blood-clot to the vessel-walls rather 

 tightl}' on one side, loosely on the other, b. Small collateral 

 branch. 



Fig. 4. Apex of the thrombus represented in Fig. 2, mao-- 

 nified 200 diameters, a. Top of third laminated portion of 

 thrombus. /. Lower stratum of the homogeneous clot consti- 

 tuting the apex. /'. Middle stratum, f". Upper stratum. 

 The white corpuscles are seen at regular intervals, and a few 

 epithelial cells are present. 



The 94-hour thrombus supplied the preparations for the 

 succeeding examination. It was found that the blood-clot now 

 extended a little higher. Its constitution was similar to tliat 

 of 48 hours, except that it was not capped with an apex of 

 homogeneous formation. The plastic clot had much increased 

 in thickness, both at the bottom and sides of the vessel. The 

 thickening of the cellular layer of the intima extended higli up 

 the walls of the artery. The cells constituting the plastic clot 

 were somewhat larger and more spindle-shape, with larger and 

 longer i)rocesses than before. Some tendencj' to form a foun- 

 dation for the development or vessels might be inferred from 

 a rather uncertain ari'angcment of some of the spindle-form 

 cells in rows. Sections were made from three thrombi of this 

 age. In those from one of them the plastic clot was observe<l 

 to send shoots a short distance into the divisions between the 

 laminated portions of the blood-clot. The latter presented no 

 otlier signs of organization. In those from tlie otlior two 

 preparations this relation between the plastic and filirinoua 



