398 



LECTURE XVI. 



Hence arose the description of Haller, that the pultace- 

 ous, atheromatous mass lay in a close cavity, as it were 

 a little cystic tumour between the internal and middle 

 coat. The only mistake was, that the tumour was re- 

 garded as a distinct body separable from the coats of the 

 vessels. It is rather the internal coat itself which without 

 any well defined limits passes into a state of degeneration 

 within the prominent spot. The farther this degeneration 

 advances, the more distinctly does an enclosed collec- 

 tion arise out of the destruction of the deepest layers of 

 the internal coat ; and at last it may be that the swelling 

 fluctuates, and that upon cutting into it the pultaceous 

 matter is evacuated, like the pus, when an abscess is cut 

 into. Now if the mass be examined which is present at 



Fig. 116. Vertical section through the walls of the aorta at a sclerotic part in 

 which atheromatous matter is already in the course of formation, m m'. Middle 

 coat, i i' ", internal coat. At s the highest point of the sclerotic part where it pro- 

 jects into the cavity of the vessel, i the innermost layer of the internal coat running 

 over the whole depot, i' the proliferating, sclerosing layer, preparing for fatty dege- 

 neration, i" the layer immediately adjoining the middle coat which has already un- 

 dergone fatty degeneration, and at e, e, is in process of direct softening. 



