358 FOLLOW THE WHALE 



probably in the Cretaceous Period. Thus we get a family tree that 

 goes like this: 



WHALES ODD-TOED UNGULATES CARNFVORES EVEN-TOED UNGULATES 



ZEUGLODONTS CONDYLARTHRA 



CREODONTS 



(ancestor) 



(ancestor) 



(common ancestor) 



After looking at such an heraldic device, many people tend to ob- 

 serve that the science of palaeontology should stick to facts and avoid 

 conjecture. There is nothing conjectural about this, however, unless 

 you do not believe in evolution, for the animals we do know must 

 have arisen from something that we do not know, and these, in turn, 

 from something before those; and the farther we work back along, 

 or down, any such family tree, the more the ancestral types converge 

 and come to resemble each other. 



Although we know these ancestors of the whales existed some- 

 where and at some time, we unfortunately do not know what the 

 original land-living forms looked like. Yet, our pursuit is not ended. 

 There is still one last place where we may look for clues, and this, 

 strangely, is among the existing whales themselves. Anent this, how- 

 ever, a most pertinent question arises: namely, whether this land ani- 

 mal, from which whales were descended and which we will call the 

 "First Ancestor," lived by the sea or on the banks of inland lakes 

 and rivers. Was it, in fact, a shore dweller or a swamp dweller? Did 

 it take to salt water off rocky coasts, as the sea otter and seals seem 



