Treatise Upon the Genesis and Development of the Dental Follicles to the Epoch of the Eruption of the Teeth. [Volume: 2, Issue: 9, April, 1861, pp. 475-486]

480

THE DENTAL COSMOS.

small obscure mass appears in the middle of each of these festoons-these
masses are the bulbs; in the ruminating animals those of the four large
incisors appear first and the four small ones afterward. At the beginning, these bulbs are nearly round, the transverse diameter being greater
than the vertical; the lower edge is distinctly marked, while the upper
edge remains diffuse. When the bulb reaches a certain size, a dark grayish band is formed around it-this represents the follicular wall. The
band, after circumscribing the base of the bulb, is lifted above it a distance which at the highest point is nearly equal to its own height, in the
ruminating animals, (Plate II. fig. 1, f;) but the distance is very much
less in man, and in the hog. This band indicates the presence of a sack,
but open on the side of the mucous membrane, and the free edge of which
reunites with itself a little later, so that, at the time, the follicle is shut,
and its cavity is soon divided exactly into two parts-for the reason that
the organ of the enamel originates as soon as the occlusion is effected;
the lower part is occupied by the bulb, and the upper is filled by the organ
of the enamel. When the follicle is thus completed it presents, in the
incisors and canines, an ovoid shape lengthened vertically. The bulb
then increases considerably, and becomes of greater height than breadth;
the summit, at the same time assuming the form of a cone a little flattened
from before backward, in such a manner that the organ exhibits the external configuration of an angle similar also to that of the future crown.
From the time that the follicle of the molar is completed by the occlusion of its wall, the diameter, in man, is nearly equal in all directions;
but it soon becomes broader than it is high. In most of the other mammiferse, it shows this particularity from the time of the occlusion of its
wall: it is nearly ovoid in the direction of the length of the jaw, and not
in the direction of its height.
A short prolongation of the wall is seen at the summit of all these follicles a little after the occlusion of the wall, and at the side where the wall
has been. This prolongation is formed, like the wall itself, of fibres and
vessels. It crosses to the mucous membrane, and its own capillaries are
anastomosed with those of that membrane. (Plate I. fig. 1, i.)
In all the mammiferoe and in the reptiles, the bulb at this period shows
itself in the form of a small, grayish mass, a little darker than the surrounding tissue from which it is not separated by anything-it is even in
continuity of substance with it at the base. But the remainder of the
periphery, although immediately contiguous to it, is easily detached, and
has a smooth and very clearly defined surface. The grayish color of the
bulb, and its want of transparency, in comparison to the surrounding
tissue, arises from the fact that it is formed, from the time of its appearance, of finely granulated ovoid nuclei, which we will speak of hereafter.
They are separated from each other a little, by a small portion of amorphous matter, which is more granulated and much less abundant than in
the surrounding tissue.