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138 HUNTER ON THE TEETH.
afterwards with the new formed basis of the Tooth : whatever
eminences or cavities the one has, the other has the same, but
reversed, so that they are moulded exactly to each other.
In the Incisorcs it lies in contact not with the sharper cutting
edge of the Pulp, or Tooth, but against the hollowed inside
of the Tooth ; and in the Molares it is placed directly
against their base, like a Tooth of the opposite Jaw. It
is thinner than the other Pulp, and decreases in proportion
as the Teeth advance. It does not seem to be very vascular.
The best time for examining it is in a Foetus of seven or eight
months old.
In the granivorous animal, such as the horse, cow, &c, whose
Teeth have the Enamel intermixed with the bony part, and
whose Teeth, when forming, have as many interstices as there
are continuations of the Enamel, we find processes from the
Pulp passing down into those interstices as far as the Pulp
which the Tooth is formed from, and there coming into contact
with it.
After the points of the first described Pulp are begun to

columns were terminated by delicate processes, which must, at the time
of separation, have been withdrawn from the interior of the partially-
calcined fibres, and must consequently have passed through the mem-
brane which is supposed to separate the two tissues." (1) Mr. Tomes
concludes from preparations in his possession " that the columns of the
enamel organ must be regarded as subservient to the development of the
fibres, the conversion of the one into the other taking place in the follow-
ing manner :—The proximal end of the column becomes calcined, not
uniformly throughout its thickness, but the outer surface or sheath first
receives the salts of lime, and at the same time the columns become
united laterally. At this point, that is, at the extreme margin of calci-
fication, the columns readily separate from the fibres, and leave a surface
which, when looked upon directly, has the appearance of a membrane,
the reticulate character of which is due to the withdrawal of the central
portion of the calcifying column," this central portion being the process
described above. (2)]

(1) Tomes op. cit., p. 267.
(2) Op. cit., p. 270.