528 TUMORS. 



reveals in the cement-substance masses of living matter which tend unques- 

 tionably toward the formation of new epithelial bodies. The initial stage of 

 such formation is a growth and confluence of the thorns into rods or spindle- 

 shaped masses, which remain in connection with the neighboring epithelia by 

 means of delicate threads. Such a change in the bulk of the living matter is 

 possible only after the liquefaction of the horny cement-substance. An increase 

 in the bulk of the thorns is invariably accompanied with a widening of the 

 space occupied by the cement-substance. Of course, the larger the formations 

 of living matter between the epithelia become, the larger must become the 

 space in which they are located ; and this enlargement often leads to the produc- 

 tion of bay-like excavations along the walls of contiguous epithelia. Such 

 excavations sometimes hold irregular clusters of bodies, which in their optical 

 behavior are identical with the nuclei of epithelia generally. The preliminary 

 stage in the development of a new epithelial body is completed by the appear- 

 ance of a coarsely granular plastid, between the old finely granular epithelia 

 and the appearance of lines of new cement-substance around the newly 

 formed body. Changes similar to those that go on in the cement-substance 

 also occur in the interior of the nuclei. Nuclei of a dumb-bell shape, or two 

 nuclei within one epithelial body, have long been known as common features 

 in epithelia. They certainly seem to point to a multiplication of nuclei, but I 

 am unable to say whether they have anything to do with new formation of 

 epithelia or not. (See Fig. 219.) 



As an addendum I may state that I have found, in microscopical sections 

 made from a papilloma of the penis, a so-called venereal wart, the same 

 characteristic features that I have described as belonging to papilloma of 

 the larynx. 



A. Biesiadecki was the first to draw attention to the presence of shining, 

 spindle-shaped bodies within the cement-substance of inflamed (eczematous) 

 skin, in which an active new growth of epithelia takes place ; but he claimed 

 that these spindle-shaped bodies came from the connective tissue. The most 

 recent writer, E. Klein, holds a similar opinion, for he describes and figures 

 in his "Atlas of Histology," in the cement-substance of epithelium from the 

 tail of a tadpole, what he calls " branched cells" of connective tissue, which 

 "are seen to extend with their processes amongst the epithelial cells." My 

 observed series disproves, of course, any such opinion. 



What I have proved in regard to the new formation of epithelia is that : (1) 

 Epithelium multiplies from medullary elements not distinguishable from those that 

 form connective tissue at the boundary between these two tissues; (2) epithelium 

 multiplies from the new growth of medullary elements which originate in the living 

 matter the so-called thorns within the cement-substance. 



11. ADENOMA. GLANDULAR TUMOR. 



Adenoma is composed of a myxomatous or fibrous connective 

 tissue, containing newly formed glands of either the acinous or 

 tubular varieties. Blood-vessels are found only in the connective- 

 tissue portions. The most characteristic feature of the glands is 

 the central caliber, which is invariably found in both the acinous 



