Dentition of \)\M\)\\y». 291 



the (liMital ludiniciit and lias a more or less distinctly swollen 

 termination. The canine which follows has already attained 

 a considerable size ; nothing more than remains of an ej)ithelial 

 cord lying- on the inner side of it is still to be seen. Its base 

 lias still not entirely disaj)peared from the frontal sections, 

 when the rudiment of the first ])remolar is already visible 

 above it. The latter also exhibits on the inner side a cord of 

 epithelium with a rounded end running from the neck of the 

 enamel-organ. It was in vain that 1 sought in the gap, 

 which occurs between this premolar and the one immediately 

 following, for a possible tuotli-rudiineiit which had disappeared, 

 the existence of which has been rendered so probable by 

 Thomas's investigations : I found nothing whatever ; on the 

 contrary, the gaj) appeared to be relatively smaller than in 

 the adult. The second premolar, which coines next (which 

 is therefore the third according to Thomas), did not show the 

 looked-for cord of epithelium, which only a|)peared again 

 beside the third premolar. The dental rudiment itself is 

 already well developed in all parts ; the epithelial cord lying 

 on the inner side of it ends in a knobbed swelling of consider- 

 able size. This concludes the investigation of the premolars ; 

 the next sections show us the conditions in the case of 

 the molars. I was very much astonished when I saw inter- 

 nally to the rudiment of the first molar also, a short but 

 distinct cord of epithelium running close beneath the epithe- 

 lium of the cavity of the mouth, and still more so when the 

 second molar also exhibited a similar epithelial cord. The 

 conditions here were very distinct : the short and somewhat 

 bent neck of the epithelium of the enamel-germ gave off on 

 the inner side a lateral cord, which was of tolerable length 

 and which thickened at the end laterally, on the inside of the 

 dental rudiment, into a knobbed swelling of considerable size, 

 precisely as we saw in the case of the third premolar. la 

 connexion with this attention must also be directed to the 

 following points : — The lateral knob of epithelium lies at a 

 tolerable distance on the inside of the rudiment of the second 

 molar, which has already completely developed its separate 

 cusps ; these have the same number and arrangement as in 

 the adult animal. Moreover, the epithelial knob is absolutely 

 lateral and not posterior in position : it has already disappeared 

 in sections in which the rudiment of the second molar is still 

 distinctly present. liudiments of teeth beyond the second 

 molar are not yet to be found. 



I am now able to furnish abundant confirmation of the 

 foregoing results, in consequence of the examination of two 

 stages somewhat more advanced in development and measuring 



