In the first periods of existence, the articular fibro-cartilages are
much developed, which appears to be the effect of the size of the
articulations at this period. In fact, as the extremities of the bones
are larger in proportion, whilst they are cartilaginous, than when they
are in the osseous state, the articulations are also proportionally
larger, and the organs they contain more developed.
The fibro-cartilages of the grooves, which are found almost all, as
we know, situated at the extremities of the long bones, are not, in
the first age distinct from the cartilages of ossification, which then
form these extremities. Confounded with them, they exhibit no line of
demarcation when we cut the lines at that place. This state continues
until complete ossification; then the fibro-cartilages of the grooves
remain insulated like the cartilages of the osseous extremities.
The interposed gelatinous portion appears to predominate, in childhood,
over the fibrous portion in the articular fibro-cartilages and in those
of the grooves. It is remarkable in the intervertebral substances,
in which this kind of mucilage which occupies the centre, is as to
quantity in the inverse ratio of the age, and in which the fibres are
also more developed. On the pubis, the whole is almost homogeneous in
the fœtus; the transverse fibres do not become very apparent till a
more advanced age. The articulations of the knee, the jaw, &c. have
in their fibro-cartilages, the same arrangement. Ebullition extracts
from them then a much greater quantity of gelatine; they have more the
smooth appearance of the cartilages.
The membranous fibro-cartilages are in general developed early, those
of the ear, the eyes and the nose especially. We see them very evident
in the fœtus. I have observed in two acephalous infants, that, like
all the other parts of the face, they were of a remarkable size, and
much greater than that of the ordinary state. Besides, the whole
fibro-cartilaginous system is, in the fœtus, extremely soft, supple and
unresisting.