TUMORS. 509 



myeloma-tissue, and many of the spindle-shaped bodies merged into the fibers 

 separating the groups of myeloma elements. Here, therefore, a new forma- 

 tion had arisen mainly from the " prickles," while a direct transformation of 

 epithelia into myeloma elements could not be demonstrated. (See Fig. 205.) 



Transformation of epithelium into myeloma elements. The tumor of the 

 testis(3) clearly exhibited the changes of the epithelia of the seminiferous 

 tubules caused by the growth of the myeloma. Even low powers of the 

 microscope demonstrated that the myeloma tissue had in numerous places 

 pushed apart the seminiferous tubules, which in other places were entirely lost. 

 In a number of specimens, not only the boundary layer of the tubules to- 

 ward the epididymis was found to have disappeared, but the glandular epithe- 

 lium itself presented, in part at least, features identical to those of the tumor. 

 (See Fig. 193.) Higher amplifications explained satisfactorily this peculiar 

 condition. The epithelium, in a transverse section of the tubule, appeared 

 in part to be well preserved, while in another portion of the same tubule 

 some of the epithelia exhibited coarse granules and solid lumps the size of 

 nuclei. A striking feature was that in one epithelium an unchanged portion 

 was found, and another portion was in the condition above described. Finally, 

 there were portions in which the epithelium was replaced by myeloma tissue, 

 in which its gradual stages could be traced. The increase of the living 

 matter first gave rise to the formation of coarse granules and new nuclei ; 

 next, new boundary lines originated within the epithelia, dividing them into 

 elements which bore no resemblance to the epithelia. Finally, the newly 

 formed elements were partly infiltrated with basis-substance, the perinuclear 

 form of which is characteristic of embryonal and lymph-tissue, as well as of 

 certain so-called " small-cellular" varieties of myeloma. (See Fig. 206.) 



The result of these changes is a real and complete transformation of the epithe- 

 lia into myeloma tissue. Here and there I met in this tissue groups composed of 

 6-12 epithelia, which in all evidence were remnants of former glands or ducts, 

 but not a glandular new formation. In all specimens of this tumor the 

 spindle-shaped bodies which sprung from the cement-substance were in dis- 

 tinct connection with the reticulum of the myeloma tissue ; and all. forma- 

 tions of living matter (granules, nucleoli, nuclei, spindles, and trabeculse) 

 were interconnected by delicate filaments. Even in the perinuclear, mucoid 

 basis-substance, in some places the bioplasson reticulum could be seen without 

 the aid of re-agents. 



In the case (5)1 obtained a distinct view of the changes of the liver-epithelia 

 in growth of myeloma. Low powers of the microscope proved that the newly 

 formed myeloma nodules were separated from the surrounding liver-tissue by 

 a tolerably thick capsule of connective tissue. Inside the capsule was a mye- 

 loma of alveolar structure j outside of it tracts of liver-epithelia were com- 

 pressed, spindle-shaped, and running in a direction parallel to the surface of 

 the capsule. In some places the boundary line between myeloma and liver- 

 tissue was not sharply marked, but merely indicated by delicate bundles of 

 connective tissue. Probably, these were the myeloma nodules of later 

 periods. (See Fig. 207.) Here, in some places, the tracts of the liver- 

 epithelia were well preserved, while in other parts the epithelium was broken 

 up into globular or irregularly shaped bodies, which could only have origi- 

 nated from the living matter in the epithelium. These bodies presented all 

 the stages of transformation into myeloma tissue ; for, upon approaching the 

 myeloma nodule, they were seen in groups, which, by virtue of their shape, 



