120 DARWINISM AND THE PROBLEMS OF LIFE 



numbers of huge reptiles in our own latitude. Where 

 the wind now sweeps in long waves over the fruitful 

 corn-fields, it then lashed the waves of a vast sea. In 

 this ancient sea the plesiosaurus, a gigantic reptile with 

 legs shaped into huge fins, swam hither and thither. 

 ,A head armed with sharp teeth crowned a neck eight 

 yards long. It towered far above the water, and when 

 unsuspecting fishes came along, the head shot down 

 with terrific force, to emerge again with the captured 

 prey. 



The ichthyosauria were no less deadly to the fishes 

 and still more to the cuttle-fishes, or huge polyp-shaped 

 molluscs. Something like dolphins in shape and size, 

 these reptiles disported themselves in great swarms in 

 the sea. There were also reptiles on the land. The 

 colossal dinosauri broke with heavy step through the 

 thickets, one of them, the cetiosaurus (of which the 

 brontosaurus was an American cousin), having a 

 ridiculously small head. Another huge animal was the 

 iguanodon. Like the modern kangaroo, the monster 

 stood on its great hind-legs and heavy tail, and tore off 

 masses of leaves with its small fore-limbs to thrust in 

 its horse-like mouth. In spite of their huge size the 

 dinosauri were harmless vegetarians. They had deadly 

 enemies in the megalosauri, gigantic carnivores with 

 teeth as sharp as knives. 



Even the third element, the air, had its reptiles at 

 that time. The pterosauri flew from tree to tree, 

 spreading out the flying membrane that stretched from 

 their enormously long fifth finger to the legs, and even 

 to the tail. The best known of these flying lizards is 



