290 



THE MAMMALIA. 



disappeared, the first and only permanent molar 

 of the lower jaw has already cut the gum. 



Teeth of the same kind as these milk-teeth, 

 which are wholly without any significance to the 

 individual as functional organs, but of the highest 

 interest for the history of the group, we became 

 acquainted with when discussing the Whales (p. 247). 



FIG. 51.-- Foetal Teeth of a Greenland Seal. 



The embryonal teeth of the Whalebone whales < 

 though there were no Dolphins or Sperm whales- 

 are an irrefutable proof that the Whalebone whales 

 are descended from toothed animals. In the same 

 way the case before us shows, that the milk-teeth 

 of Seals which have in our day become of utter 



