144 
HISTOLOGY OF ANIMALS. 
and the distance between the nucleus and cell-wall 
becomes much greater ; and last of all, close to the 
attached surface B, we find spicula or lines, projecting 
between the parallel rows of cells ; these are sections 
FIG. 113 . 
A 
B 
Vertical section of articular carti- 
lage from the head of the humerus 
of a fcetal Wolf: a, articular surface. 
b, attached surface. 
fig. 114 . 
A 
B 
Vertical section of articular carti- 
lage from a human metacarpal bone: 
a, articular surface, b, bone of the 
shaft, c, articular lamella. 
of the walls of tubes of newly-formed bone, and 
which, when fully developed, become solid, each having 
enclosed a column of large cartilage-cells. In many 
sections of articular cartilage, as in Fig. 113 , A, taken 
from the head of the humerus of a young Wolf, there 
are foramina through which blood-vessels pass to nourish 
