RUDIMENTARY ORGANS. 89 



the unborn young of ruminants, or animals which "chew the 

 cud ; " these animals in their adult state possessing no front teeth in 

 the upper jaw, but in their immature condition developing these 

 organs which, by the way, never cut the gum only to lose them by 

 a natural process of absorption. Now, here there can be no question 

 of use ; and certainly no adequate explanation of their occurrence 

 exists, save that which regards these foetal teeth as the remnants of 

 structures once well developed in the ancestors of the whalebone 

 whales and ruminants. To this supposition the evidence avowedly 

 incomplete obtained from geology gives no contradiction, even if it 

 does not by any means supply the " missing links " in an adequate 

 fashion. We do know that amongst the oldest of the great 

 leviathans of the past was the Zeuglodon, of Tertiary rocks, which had 

 teeth developed much in excess of anything we find represented in 

 the dental arrangements of the whales of to-day a creature this, of 



FIG. 28. DODO. FIG. 29. SOLITAIRE. 



which, as regards its teeth at least, modern whales are but shadowy 

 reproductions. Whilst under the shelter of great authority, we may 

 declare this ancestor of the whale to have been intermediate in nature 

 between the seals and whales, or between the whales and their 

 neighbours the manatees or sea-cows and dugongs. In either case, 

 the intermediate character of the animal argues in favour of its 

 having been the likely parent of a race dentally degraded in these 

 latter days. 



There is little need to specialise further instances of the occurrence 

 of rudimentary organs in the higher animals, save to remark that not 

 the least interesting feature of such cases is contained in the fact that 

 the milk-glands of male animals amongst quadrupeds organs which 



