374 C. DA FANO 



of cells provided with an apparatus of the characteristic type 

 described varied considerably from tumour to tumour and from 

 place to place of the same tumour ; but whenever the absorption 

 process had manifested itself, the apparatus showed in varying 

 degrees the changes shown in PI. 19, fig. 4. 



It is interesting to note that the same fact was even more 

 clearly observed in dividing tumour cells. Mitotically dividing 

 cells frequently occur in spontaneously absorbing tumours 

 even when these are much reduced in size and nearing complete 

 disappearance. One of such cells is shown in a part of PI. 19, 

 fig. 4. and another in the centre of PI. 20, fig. 5. In both cases 

 the fragments of the apparatus (dictyosomes) to be subdivided 

 between the daughter cells no longer have the aspect generally 

 observed in growing tumours of small solid clumps of argento- 

 pliile material, but appear as irregularly rounded or elliptical 

 shapes with a light central portion, as in most of the absorbing 

 cells at rest. PL 20, fig. 5, was drawn from a specimen of 

 a tumour in a very advanced phase of absorption, and the 

 apparatus of some cells show' signs of the approaching com- 

 plete disintegration. 



Tumours 91 and 20 6. — The apparatus of the healthy 

 cells of these two growths has a fine reticular structure, more 

 delicate in carcinoma 206 than in carcinoma 91. During 

 absorption the characteristic aspect of the apparatus is still 

 recognized for a time in the cells of both of them. In the case 

 of tumour 91, however, the apparatus is soon reduced to a 

 granular material with loss of the previous reticular arrange- 

 ment. This is well shown in PI. 20, fig. 6, which was drawn from 

 a place where the various phases of this degenerative process 

 could be seen one next to the other. In other areas of the same 

 absorbing tumour, appearances almost identical with that ex- 

 hibited by the central portion of PI. xxii, fig. 32, of the previous 

 work were sometimes noticed. In such instances the similarity 

 between the disintegrative phenomena affecting the apparatus 

 of both the tumours now considered was rather striking, though 

 in carcinoma 206 the gradual fragmentation of the previous 

 fine network was plainer. As shown by PI. 20, fig. 7, a reticula 



