172 
HISTOLOGY OF ANIMALS. 
FIG, 133 . 
Vertical section of ossifying 
cartilage from the humerus of 
a foetal Wolf. 
the other, B, the granules of ossific matter around the 
cells are well shown. A good 
example of intercellular ossifica- 
tion has already been given in 
Fig. 127 , b. When a cartilagi- 
nous epiphysis is undergoing 
the process of ossification, the 
cartilage-cells first arrange them- 
selves in linear series, and at the 
period of ossification, the cell- 
walls, as in Fig. 133, become 
more widely separated from the 
nucleus, whilst the cells themselves are studded with 
minute ossific granules ; if a section be made at right 
angles to the shaft, the walls of the cartilage-cells, as 
represented by A, in Fig. 134, 
will be found thickened by 
the granular deposit; subse- 
quently, tubes of bone shoot 
up between the cells, and so 
enclose them. The part in 
which this process is going on 
may be readily distinguished 
by the arrangement of the 
cartilage-cells. In a vertical 
section of one of the short 
phalanges from the foot of a young Pig , Fig. 135, 
a thin layer of cartilage will be seen between two 
pieces of bone ; if this be more closely examined, it 
FIG. 134 . 
ft m 
a, transverse section of ossify- 
ing cartilage from humerus of 
foetal Wolf, b, osseous granules 
from cranium of a Canary. 
