678 APPENDIX. 



the interior filling up with large granulations (as in d). Within 

 these nuclei, when they have not been obscured by granular or 

 fatty degeneration, there is found, habitually, a small^bpdy, or 

 nucleolus, averaging in diameter about l-500th of a millimetre. 



FIG. 384. 



Pus-corpuscles after acetic acid. Free cancer nuclei. 



These nucleoli have somewhat of a yellowish tinge, with a bril- 

 liant centre and dark borders, refracting light like the fat-vesicles. 

 We would call attention, particularly, to the peculiar brilliancy 

 of the centres of these nucleoli, which, we think, is characteristic; 

 it can almost invariably be noticed, if the focus is varied. Their 

 large size, in proportion to the nuclei, should also be noticed, 

 together with the great variableness of their position, sometimes 

 being near the centre, and again in close contact with the walls 

 (see Fig. 384, e). Ordinarily, in other elements, they are found 

 almost constantly in the centre. Very frequently two or three nu- 

 cleoli are found within the same nucleus. M. Eobin 1 mentions 

 the action of acetic acid upon cancer-nuclei and their nucleoli as 

 differing from that on other elements, particularly epithelial ; it 

 renders the nucleus gradually paler, together with the cell, de- 

 stroying neither, but the nucleolus is perfectly untouched by it; 

 whereas, in epithelial cells, where generally in those of the skin 

 the nucleoli are wanting, the action of acetic acid destroys the 

 cell, leaving the nucleus unaltered." 



The polygonal shape may be regarded as the typical form of 

 the cancer-cell. "In hard firm tumors, particularly those of the 

 breast and ovaries, the cells found are exceedingly irregular, some- 

 times nearly triangular. (Fig. 385, /.) The ovoid or spherical 

 are more frequently met with in soft or medullary cancer (Fig. 

 386, ^r), where there is but little pressure, although its juice appears 

 often to be but one mass of cells. It is rare, however, that per- 

 fectly round cells are met with, but very generally the angles are 

 well rounded in those which appear to be derived directly from 



1 MS. notes of his Cours de Histologie, 1850. 



