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to each socket, which are situated rather laterally, that is to
say, at a greater distance from the symphysis of the jaw,
than the centre of each respective temporary socket. These
niches do not penetrate so deep as to the bottom of the tem-
porary sockets, but increase in proportion with the size of the
permanent sacs, and gradually form a distinct socket round
each of them. There is, however, an opening left imme-
diately under the gum, through which the membranes of both
sets of teeth continue to be connected. The pulps of the
incisores in general are so far advanced at birth, that soon
after ossification commences on them. In a child about six
or seven months old, I found their shells much more advan-
ced than, a priori, I could have expected, and those of the
cuspidati also had begun to ossify. The sacs of the bicus-
pides which succeed the anterior grinders had appeared,
yet I did not remark those which were to succeed the pos-
terior grinders, although those of the middle permanent
grinders had already commenced.
In a child about four years old, the bodies of some of the
permanent teeth were very much advanced, ossification had
commenced on the bicuspides, all the points of ossification
of the middle grinders were united, and the membranes of
the posterior grinders or wisdom-teeth were forming. I
have examined a number of children's jaws about this age,
and found in general a similarity of appearance with re-
spect to the number of teeth which were then formed, and
also those which were forming. So that I may safely say
there are more teeth formed and forming at this, than at any
other period of life, that is twenty-six teeth, in each jaw.
Soon after the sacs of the permanent teeth have com-
menced, a very curious and beautiful process takes place,
for they retain their situation at the bottom of the jaws,
whilst at the same time, the temporary teeth rise and appear