876 C. DA FANO 



be attributed to the process of involution through which also 

 the proliferated connective-tissue cells presumably pass before 

 disappearing with the remains of the tumour. 



Together with the giant cells, either in the same situations 

 or between the keratinized nodules, elements of the large 

 wandering cell type were frequently observed. They were 

 provided with a small either reticular or compact apparatus 

 similar to that of elements of the same kind previously men- 

 tioned and described also by Verson (17), though in different 

 pathological conditions. 



3 7 S . — In the absorption areas of this sarcoma of the mouse 

 the apparatus undergoes a simple process of granular disinte- 

 gration, frequently manifesting itself at a period in which the 

 outward aspect and structure of the tumour cells is otherwise 

 almost unaltered. Apart from the size of the cells, the pheno- 

 menon is like that observed in the foreign body giant cells 

 described in connexion with PI. 20, fig. 8. As easily deduced 

 from a comparison between PI. 20, figs. 8 and 9, in both cases 

 the apparatus soon becomes transformed into an accumulation 

 of small argentophile granules, the arrangement of which now 

 and then reminds one of a pre-existing reticular structure. 

 This observation is not without interest, because the cells 

 exhibiting the changes described have in common a connective- 

 tissue origin. PI. 20, fig. 9, was drawn from the peripheral portion 

 of a nodule, the central cells of which still appeared in a healthy 

 condition and possessed an apparatus identical with that 

 shown in PI. xvi, fig. 19, of the previous work. Only a few of 

 the peripherally situated cells were provided w^ith an intact 

 apparatus, though remains of it could be recognized even 

 in elements showing many signs of degeneration, such as loss 

 of a great part of the nuclear chromatin, liquefaction, and 

 fusion of the cell-bodies. 



General Coxsiderations. 



One of the principal facts resulting from the present investiga- 

 tion is the relative resistance of the apparatus to altered 

 biological conditions even when these lead to a complete 



