where, however, it is the milk dentition that is most pronounced, the "permanent" being feeble and very early shed.
Fig. 227.—Skeleton of Seal. Phoca vitulina. (After de Blainville.)
But the dentition of the Pinnipedes presents other likenesses to the Cetacea, which are, it must be remembered, regarded by some as a modification of the Carnivorous stock, in which case, of course, the likenesses may be genetic rather than due to adaptation in the two cases. There is a distinct tendency towards a homodont series, the grinding teeth being often very simple, and the very distinct carnassial tooth of many terrestrial Carnivores being absent. Finally, the number of the back teeth shows some signs of being on the increase; and Professor Kükenthal has found that this increase is due to the division of existing teeth. Here is a point of likeness to the many teeth of the typical Toothed Whales. Dr. Nehring found in several examples of Halichoerus grypus the normal five back teeth increased to
