THE INCREDIBLE SHARKS 333 



contemplates the fact that they were pursuing their prey and 

 engaging in the activities of their kind when the soUd earth was 

 nothing but an empty space of sUmy mud or dusty desert, 

 where nothing moved or stirred and where no voice broke the 

 stillness, that respect must be tinged with wonder. 



Eventually, when the land did become carpeted with vege- 

 tation, when the amphibians had their grotesque hour and then 

 disappeared, to be followed by the still more weird reptiles— 

 by the gigantic dinosaurs, the ichthyosaurs and the pterodac- 

 tyls—when the ocean was the abiding place of the ferocious 

 mosasaurs, which descended from the land into the sea, the 

 sharks maintained themselves as they had from time immem- 

 orial. When the reptiles were gone in their turn, and when the 

 dawn of the age of mammals broke upon the face of the earth 

 just as it is now in our time rapidly coming to a swift and un- 

 fortunate close these persistent sharks blossomed into a numeri- 

 cal abundance which must have been amazing, if we could 

 only have been there to witness it. 



My earliest memories of fossil hunts bring recollections of 

 finding myriads of shark teeth. At the base of the famous blue 

 cHffs of the Miocene in Maryland along the shore of the Chesa- 

 peake Bay I have in a single day picked out of the sand and 

 clay a thousand shark teeth from a strip of cKff and beach 

 several hundred yards long! Sharks must have swarmed in 

 legions to have left so many teeth in one spot. These ranged 

 in size from tiny points a quarter inch in length to large tri- 

 angles five inches from apex to root. It has been estimated that 

 these latter teeth must have been borne by animals ranging 

 from a hundred to a hundred and twenty feet long, the largest 

 living organisms of all time? A man could have easily sat 

 in the open mouth of one of these monsters. They apparently 

 persisted into comparatively recent times for hundreds of simi- 

 lar teeth have been dredged from the ocean bottom. We have 



