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front teeth were quite separate from each other ; and in one
case the middle incisores were nearly half an inch asunder,
though there was no defect in the palate.
From what is now said I feel myself justifiable in conclud-
ing, that the alveolar arches continue to increase during the
entire progress of the formation of the teeth : it is however suf-
ficiently evident, the greatest increase ofthe jaw is backwards.
I do not by any means deny but that we frequently meet
with disproportions between the jaws and teeth, and such
that the permanent teeth never would become regular with-
out the assistance of art, even in young persons ; this may
arise from the resistance of the temporary teeth, or from
teeth forming so much out of the circle that they have not
sufficient power to act on their neighbours and press them
back, such as the cuspidati, which are most commonly irreg-
ular. Indeed if Mr. Hunter's hypothesis were true, we
should never see a regular set of teeth.
Duval concurs with Mr. Blake in considering that the
jaws increase in all parts during and before the second den-
tition, upon which he makes the following observations. Af-
ter remarking upon the situations taken by the adult teeth he
continues. " At this disposition of parts, who is not struck
with admiration ? but we shall be still more so when we
learn that the jaw bone grows transversely, in order to make
room for the permanent grinders, which are never shed, not
only by increasing in size in that part which lies behind the
temporary grinders, as the anatomists have published,* but by
developing itself equally in all its points in such a manner
that the sockets of the large grinders and these teeth them-
selves grow and become successively placed from behind

Duval, page 60.