486 LECTURE XIX. 



the extravasated blood is generally pretty completely 

 reabsorbed, and it contributes comparatively but very 

 little to the real formation of the subsequent uniting 

 media. 



We discussed, gentlemen, last time, the chief points 

 in the history of new-formations. You remember that, 

 according to our ideas, every kind of new-formation 

 inasmuch as it has its origin in pre-existing cellular ele- 

 ments and takes their place must necessarily be 

 connected with a change in the given part of the body. 

 It is no longer possible to defend an hypothesis such as 

 that which, based upon the supposed existence of plastic 

 matters, was formerly maintained, namely, that a sub- 

 stance was deposited between and upon the existing 

 elements of the body, which produced a new tissue out 

 of itself and thus represented a clear accession to the 

 body. If it is true that every new-formation proceeds 

 from definite elements, and that usually divisions of the 

 cells are the means by which the new-formation is pro- 

 duced, it becomes of course self-evident that where a 

 new -formation takes place, certain histological elements of 

 the body must generally also cease to exist. Even a cell, 

 which simply divides and out of itself produces two new 

 cells like itself, thereby ceases to exist, even though 

 the whole result is only the apparent apposition of a 

 cell. This holds good for all kinds of new-formations, 

 both for benignant as well as for malignant ones, and it 

 may therefore in a certain sense be said, that every kind 

 of new-formation is really destructive, and that it destroys 

 something of what previously existed. But we are, as it 

 is well-known, accustomed to judge of destruction 

 according to the more obvious effects produced, and 

 when we speak of destructive formations, we do not so 

 much mean those, in which the result of the new-forma- 



