TUMOES. 



497 



could be found ; therefore, they were decidedly malignant. In 

 tumors of this sort the multinuclear plastids were always scanty 

 and imperfectly developed i. e., composed only of clusters of 

 medullary corpuscles. The comparatively benign type of " epulis," 

 however, is more common than the malignant. (See Fig. 197.) 



Any myeloma, including the alveolar myeloma, may be the seat 

 of a more or less abundant formation of pigment, and is then termed 

 melanotic myeloma. The pigment, therefore, is merely an inci- 

 dental feature of myeloma, but it is known to increase greatly 

 the malignancy of the tumor. The origin of the pigment was 



FIG. 196. SPINDLE-NET MYELOMA, FROM THE SUBCUTANEOUS 

 TISSUE OF THE LEG OF A MAN. 



S, nucleated spindles branching and uniting ; the meshes contain a finely granular myxom- 

 atous basis-substance, and G, apparently isolated globular or oblong plastids. Magnified 

 600 diameters. 



formerly attributed to extravasated blood. I have ascertained 

 that in such tumors a very profuse new formation of living 

 matter takes place, which causes the production of numerous 

 haematoblasts, i. e., solid lumps of living matter, which in their 

 earlier stages of formation, for reasons unknown, are supplied 

 with the coloring matter of the blood. (See page 98.) From 

 32 



