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/2 EMBRYOLOGY OF THE DENTAL TISSUES.
times found in folds. These have been called " papilliform eminences,"
and are seen to be projecting into or near the enamel cells. To this
appearance some authors attach considerable importance, but it is

Fig. 53.

Section of jaw, embryo of pig, showing dental follicle: 1, dental follicle, consisting of enamel
organ, dentin germ surrounded by the sacculus within the substance of the jaw ; 2, jaw-bone ;
3, tongue ; 4, papillary layer of tongue.

doubtful if it has any significance. It, like the folds in many other
embryonic tissues, is to be taken up by the expansion of the part by
growth.
In regard to the cement organ, Tomes says : " In those creatures
which have comentum upon tlie roots of the teeth only, no special cov-
ered organ exists ; but osteoblasts, which calcify into cementum, are
furnished by the tooth sac."
The gubernaculum is a thin fibrous cord of dense tissue, connecting
the permanent tooth follicle in its bony shell with the gum tissue just
back of the neck of the corresponding temporary teeth. It is a struct-
ure of no importance.