166 
HISTOLOGY OF ANIMALS. 
in a fibrous matrix; others, in the same tumour, as 
at b, can be separated from the matrix, proving that 
they are true cells, and not mere vacuities in the 
hyaline substance. In order to demonstrate that these 
cells are, in all probability, altered nuclei, the original 
cell-walls of which have disappeared, I shall describe 
the structure of a section of the enchondromatous 
tumour of the leg, before referred to in page 164, as 
having been lately removed by Mr. Lloyd at St. 
Bartholomew’s Hospital ; it was a large mass, measur- 
ing twenty-two inches in circumference, and very 
thin sections exhibit cells of an oval or circular figure, 
having a central nucleus and a concentric laminated 
deposit. Some of these, represented in Fig. 127, b , 
exhibit a minutely granular structure, as though ossifi- 
cation had commenced in them ; other parts of the 
section exhibit cells of similar size, in which the nucleus 
is not only well developed, but occasionally small pro- 
jecting points, like commencing canaliculi, may be 
observed, as in Fig. 127, a. As soon, however, as 
the canaliculi become somewhat more evident, the 
cell-wall disappears, and we then find cells of similar 
shape to those in the first specimen, but of larger size, 
Fig. 127, c. It sometimes happens that these cells 
are met with either above or below a cartilage cell, 
and it then appears as though the altered nucleus were 
still within a cell wall ; but careful focussing will 
prove that this view of their relative situation is incor- 
rect. In one part of the specimen, there is a thin 
