494 



TUMORS. 



of the central nervous system and the retina, without reference 

 to their intimate histological structure. Kecently, efforts have 

 been made to remove glioma from the group of myeloma. Clin- 

 ical observation shows the extreme malignity of many of these 

 tumors ; microscopic examination shows their close relationship 

 to myeloma, and that a varying amount of fibrous connective 

 tissue may enter into their construction. 



Glioma is composed of elements closely resembling those found 

 in the cortex cerebri and cerebelli, and those of the granular 

 layers of the retina. These elements exhibit comparatively large 

 nuclei, around which is a scanty rim of granular bioplasson. 



In rapidly growing tumors the elements exhibit distinct 

 proliferation, and in many instances flatten each other. Between 



FIG. 192. GLOBO-MYELOMA, COMPOSED OF SMALL PLASTIDS. 

 FROM THE TESTICLE OF AN ADULT. 



T, transverse section of a seminiferous tubule, toward the epididymis ; S, myeloma of the 

 type of lymph-tissue (adenoid tissue) ; TS, transition of the epithelia into myeloma tissue. 

 (For high amplification of the same tumor, see Fig. 206.) Magnified 200 diameters. 



them we see a delicate layer of cement-substance, traversed by 

 the connecting filaments. In the cement-substance homogeneous 

 plastids occur, indicating either development of glioma- or spindle- 

 shaped elements, which latter belong to the connective-tissue 

 frame. (See Fig. 193.) 



(B) Spindle-myeloma is composed of medullary tissue with 

 spindle-shaped elements. The difference between physiological 



