THE MICROSCOPE IN PATHOLOGY AND MEDICINE. 233 



local cells. This favors Beale's view that multiplying 

 bioplasm are the true disease germs. 



The general plan on which new formations occur has 

 been shown by Rindfleisch as : 1. The uniform enlargement 

 of an organ by increase of structural elements (hypertro- 

 phy). 2. A node, or roundish tumefaction, by interstitial 

 deposit, stretching the parenchyma. 3. Infiltration, which 

 condenses tissue in small depots. 4. Desquamation, as in 

 epithelial catarrh. 5. Flat tumefaction. 6. Tuberosity, 

 which, when narrow or finger-like, is a papillae or wart. 

 7. Fungus, spongy or ulcerated. 8. Polypus, a papilla 

 with a narrow base. 9. Dendritic vegetation, or new 

 papillae from the sides of others. 10. Cysts of retention, 

 from occlusion of ducts. 11. Exudation cysts, in closed 

 cavities. 12. Etravasation cysts. 13. Softening cysts. 



Histologically, we may divide tumors into : 



I. Histoid, whose elements correspond with normal 

 tissues. 



II. Carcinomatous, dependent on abnormal growth of 

 epithelial elements. These are generally in the skin, the 

 mucous membranes, or glands. 



The following list, after Billroth, may serve for brief 

 reference : 



1. Fibroma^ composed of developed connective tissue. 

 (1.) Soft fibrous tumors, almost exclusively in the skin. 

 (2.) Firm fibroma. Most often in the uterus, where they 

 may calcify or form fibrous polypi; sometimes on the 

 periosteum and on nerves. 



2. Lipoma, or fatty tumor. 



3. Chondroma (cartilaginous). These occur on bones, 

 are vascular, and often ossify. The softened and cystic 

 forms have been called colloid tumors, gelatinous cancer, 

 etc. 



4. Osteoma (exostosis). These may be spongy or com- 

 pact. 



5. Myoma. Billroth doubts if true muscular tumors 



