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DEVELOPMENT OF CORD FOR PERMANENT TEETH. 641
the rich plexus of capillary vessels, the latter furnishing the lime salts
for the completion of the calcification of the enamel. By referring
to Fig. 366, taken from circle d, it will be seen that a slight layer of
enamel has been formed which has the appearance of a honeycombed
layer. Between this layer of enamel and the layer of amelol^lasts a
space is noticed which was caused by shrinkage in the process of
Fig. 365.
Circle c, Fig. 3G0 (X230): dp, dental papilla; o, odontoblasts; d, dentine; sp, space; a, ameloblasts
sr, stellate reticulum.
hardening. Into this space projects a fibrillated margin of the amelo-
blastic layer known as Tomes's processes, of which we will speak later.
There exists considerable confusion regarding the outer tunic of the
enamel, organ. The most erroneous statement concerning it was pub-
lished by Waldeyer, who says : " As far as the external epithelium
reaches, the adjoining connective tissue exhibits its tolerably regularly-
formed vascular papillse, which project into the epithelium and cor-
respond to the papillae found in the remaining portion of the oral
mucous membrane." He also presents a cut which does not represent
the true condition of the enamel organ at this stage of development,
either in the human or porcine foetus. He neglects, however, to state
the age or length of the foetus—two essential points to be considered in
presenting illustrations. This cut has been extensively copied, and
those who have used it have also neglected to locate it. Now, the
outer tunic does not present indentations in its surface until it begins to
break up; it is smooth and even, like the inner- tunic, until the time
comes for its disappearance. The history of its retrogression can be
followed as carefully as can the progression of the inner tunic. If we
examine Fig. 363, taken from circle h of Fig. 362, we shall be able to
Vol. I.—41
DEVELOPMENT OF CORD FOR PERMANENT TEETH. 641
the rich plexus of capillary vessels, the latter furnishing the lime salts
for the completion of the calcification of the enamel. By referring
to Fig. 366, taken from circle d, it will be seen that a slight layer of
enamel has been formed which has the appearance of a honeycombed
layer. Between this layer of enamel and the layer of amelol^lasts a
space is noticed which was caused by shrinkage in the process of
Fig. 365.
Circle c, Fig. 3G0 (X230): dp, dental papilla; o, odontoblasts; d, dentine; sp, space; a, ameloblasts
sr, stellate reticulum.
hardening. Into this space projects a fibrillated margin of the amelo-
blastic layer known as Tomes's processes, of which we will speak later.
There exists considerable confusion regarding the outer tunic of the
enamel, organ. The most erroneous statement concerning it was pub-
lished by Waldeyer, who says : " As far as the external epithelium
reaches, the adjoining connective tissue exhibits its tolerably regularly-
formed vascular papillse, which project into the epithelium and cor-
respond to the papillae found in the remaining portion of the oral
mucous membrane." He also presents a cut which does not represent
the true condition of the enamel organ at this stage of development,
either in the human or porcine foetus. He neglects, however, to state
the age or length of the foetus—two essential points to be considered in
presenting illustrations. This cut has been extensively copied, and
those who have used it have also neglected to locate it. Now, the
outer tunic does not present indentations in its surface until it begins to
break up; it is smooth and even, like the inner- tunic, until the time
comes for its disappearance. The history of its retrogression can be
followed as carefully as can the progression of the inner tunic. If we
examine Fig. 363, taken from circle h of Fig. 362, we shall be able to
Vol. I.—41
