DEVELOPMENT AND SUCCESSION OF TEETH IN PERAMELES. 533 
sane objectionable form of expression— bud-like enamel- 
germs”: “Es sind nun, wohlgemerkt, nicht etwa die Enden 
der frei endigenden, einfachen Zahnleiste, die nach innen von 
den durchbrechenden Zahananlagen der Beuteltiere liegen ” 
[but they are really nothing more], “ sondern knospenformige, 
teilweise von verdichtetem Bindegewebe umgebene Schmelz- 
keimstadien,” &c. (27, p. 655). 
Localised serial swellings of the continuous 
dental lamina in its liberated or residual phase, 
such as we can justifiably speak of as separate 
enamel-germs, do not exist, either distinguished 
from, or as integral parts of, the residual lamina 
aforesaid. 
An exception to this statement must of course be made in 
favour of p. 3, which arises in the first place as a localised 
thickening of the residual lamina by the side of dp. 3. But 
p. 8, as we shall attempt to prove more conclusively below, is 
serially homologous with the enamel-organs of the other ante- 
molar teeth of the adult, and not with the residual lamina 
developed by their sides. 
We cannot insist too strongly on the laminar character of 
the residual lamina. As we have again and again shown in 
the course of our description of stages, it arises as a result of 
the constriction process whereby the permanent enamel-organs 
are differentiated from the main dental lamina. And, when 
thoroughly established, it is in perfect morphological con- 
tinuity with the undifferentiated dental lamina fore and aft, 
intermediate between the region of one tooth and those of the 
next in front and behind. This is well brought out in our 
fig. 82, which is a combination drawing from several suc- 
cessive horizontal sections of the upper jaw of our Stage v. 
The complete antero-posterior continuity of the dental lamina 
in the anterior premolar region could not be demonstrated in a 
single section, but in the combination figure no violence has been 
done to any essential relationship. And the figure will be suffi- 
cient to illustrate the manner in which the free residual lamina by 
the lingual side, say, of p+, simply forms the direct continuation 
