Treatise Upon the Genesis and Development of the Dental Follicles to the Epoch of the Eruption of the Teeth. [Volume: 2, Issue: 11, June, 1861, pp. 587-601]

GENESIS AND DEVELOPMENT OF THE DENTAL FOLLICLES. 599

than during the foetal period; they are more numerous near the surface
of the bulb than in its depth, where they become rarer and rarer, while,
on the contrary, the fibres are more abundant. These nuclei resemble
those of the foetus, except that they are a little more elongated. It is
also to be remarked that the tissue of the coronal portion of the bulb is
softer at the surface, where they abound, than in the lower part where the
fibres predominate.
b. Vessels of the Bulb.
Near the period when the bulb reaches a breadth of about one-half or
three-quarters of a millimetre, it begins to become vascular. We see at
first one or two vascular loops extending into the thickness of the base;
but in bulbs of only a millimetre or a little more, many other loops can be
seen detaching themselves from these and advancing toward the surface
of the organ. They do not reach it, however; they do not penetrate
even as far as the superficial bed of the amorphous matter which is without
nuclei, and which forms the surface of the bulb. So long as the coronal
portion of the latter is not covered with ivory, the extremities of the
loops remain at about three or four hundredths of a millimetre from the
surface, (pl. v., fig. 3.)
A small artery, from one to two-tenths of a millimetre in diameter, and
reaching but little beyond this volume at any age, followed by one or two
small corresponding veins, show themselves at the base of the bulb or of
its radicular part, according to the age. In proportion as they reach the
narrower part of the dental germ, near its coronal portion, the vessels
subdivide a great many times at very short intervals. When the bulbs
are still small, each afferent capillary only curves loop-like near the surface of the organ, and returns directly to the veinous trunk as an afferent
capillary, (pl. v., fig. 3.)
In the whole of the divisions and loops, these vascular arrangements,
while very simple, are extremely elegant. Many of the capillaries fold
back upon themselves, in the shape of the figure 8, near the loop-extremity, at the point where they change from efferents into afferents. In addition to this, they describe some flexuosities, or very close and short
undulations. The distance between these capillaries is about two to four
times their own diameter, and continues nearly the same during the whole
existence of the bulb.
By taking follicles more and more voluminous, until the teeth are fully
developed, we find that when the loops are elongated their capillaries
communicate by transverse branches, which become more and more numerous, and thus divide them into polygonal meshes with rounded angles, the
diameter of which is from three to four times that of the capillaries which
circumscribe them. The whole is very elegant on well-injected bulbs, or,
better still, on the well-congested bulbs of suffocated animals, or on certain diseased teeth which have been extracted. We have already said