TUMORS. 



347 



present in great numbers. They spring from the reproductive 

 organs of the body, and appear to be erratic attempts at the pro- 

 duction of new individuals. 



A new formation of bloodvessels accompanies the development 

 of tumors, and these vessels are associated with a supporting con- 

 nective tissue which may be conceived as a part of this addition to 

 the vascular system of the body, rather than as an integral part 

 of the tumor itself. This development of new bloodvessels is 

 analogous to that which takes place in the course of some of the 

 inflammatory processes, and appears to be brought about in the 

 same manner. 



I. THE CONNECTIVE-TISSUE TUMORS. 



1. Fibroma. The structure of a fibroma is apt to resemble that of 

 the particular fibrous tissue in which it develops. Very soft varieties 

 frequently spring from the submucous tissues of the nose, pharynx, 



FIG. 308. 



Section of a nodular fibroma. (Birch-Hirschfeld.) The dense fibrous tissue is in irregular 

 nodules, between which are bands of less dense fibrous tissue containing blood- 

 vessels. 



and rectum, forming polypoid growths projecting from the surface 

 of the mucous membrane. They are composed of delicate bands 

 of fibres, loosely disposed to form an open meshwork, which is filled 



