Dark Is Be j ore the Dauon 359 



to have done, or did it go searching for food in swamps bordering 

 lakes or along the banks of rivers? A second important question is: 

 did this take place in a hot or a cold climate — that is to say, in cold 

 temperate or polar regions during an ice age or in the tropics during 

 such a period — or did it take place when the whole world was at 

 normal temperature, and thus tropical? These are not easy questions 

 to answer without becoming conjectural, but there are some very 

 distinct pointers to guide us, and all of these seem to direct us to- 

 wards one conclusion — namely, that the "First Ancestors" lived on 

 the banks of rivers or lakes in tropical forests. The evidence is as 

 follows: 



When primitive man "returned" to the sea, he did so by two quite 

 distinct routes, as was noted early in our tale. On the one hand, he 

 floated down rivers to gulfs and then crept along coasts, the riverine- 

 gulfine mariner; on the other, he struck out boldly from headlands 

 to islands offshore or vice versa, thereby becoming the peninsular- 

 insular sailor. In this he was only recapitulating an immensely an- 

 cient pattern ofttimes followed by all sorts of land animals. The 

 manatee and iguana lizards are of the former breed; the sea lion and 

 the sea snakes of the latter. While there is no distinctive pattern dis- 

 tinguishing one from the other, the whales display a greater con- 

 formity to the former type than to the latter, quite apart from their 

 features in common with the odd-toed ungulates. Rather, it is certain 

 aspects of their external form that give us pause to consider. 



There is a wonderful animal living today in the tropical forests of 

 South America, known as the Saro, or the Giant Otter (Pteroneura 

 braziliensis). This animal is almost wholly aquatic, and its legs have 

 been reduced to Httle stumps that cannot support its five-foot, flat- 

 tened, alligator-shaped body on land, so that it slithers along like a 

 snake. Its muzzle has become shovel-shaped and extends forward 

 over the mouth, which opens below like that of a shark. What is 

 more, its tail has developed flanges along either side, so that, when 

 looked at from on top, it has the shape of a broad spear (see Appen- 

 dix C). The whole creature is devised for diving into streams and 

 rivers, and its tail for getting down to the bottom and back up to 

 the surface again with as little effort and as great dispatch as possible. 

 Maneuvering from side to side is, to this and other riverine hunters, 

 only of secondary import. 



