20 THE TONER LECTURES. 



dense fibrous tissue, the only remains of the previous blood 

 channel 



To summarize briefly, the standard authorities publish in 

 very positive terms the opinions which they believe have been 

 indisputably demonstrated, viz.: that immediately after the 

 ligature of an artery a blood-clot is formed which plugs the lu- 

 men of the vessel, generally up to the level of the first collateral 

 branch ; that this clot is homogeneous, unstratified, is formed 

 at one time, and is larger during the first hours than at any 

 other jjeriod ; that it ofi'ers a temporary barrier to the flow of 

 blood; that soon the blood-clot thus formed, itself becomes 

 organized and supplied with its own vessels, which form a com- 

 munication first with the lumen above the clot, next with the 

 vasa vasorum mainly at the bottom of the clot ; that it is 

 by this organization and vasculaiizatiou of the temporary 

 blood-clot, and the intimate union of this newly formed tissue 

 with the vessel-walls, that the lumen of the wounded artery be- 

 comes permanently closed against the blood current ; and that 

 the organizing elements are solely and exclusively the white 

 blood-corpuscles and their descendants — either those which are 

 caught in the clot at the time of its formation, or those which 

 may have wandered into it afterward, or more probably those 

 derived from both sources. It is thus that their ideas concern- 

 ing tlie nature of the inflammatory process in wounded arteries 

 are made to coincide entirely with and to give some further 

 support to Cohnheim's theory of inflammation in general. 



PERSONAL OBSERVATIONS. 



More than three years ago, at the request of my friend Prof. 

 Agnew, of the University of Pennsylvania, and for his benefit, 

 I (with the surgical assistance of my friend Dr. Wm. Mastin, 

 of Mobile, who was at that time an Interne of University Hos- 

 pital) traversed experimentally some of the ground which 0. 

 Weber had gone over while makins: his researches relative to 



