190 THE STORY OF REPTILE LIFE. 



water, which filled up the impress with fine mud. 

 In some other cases where these footprints of 

 bipedal dinosaurs are preserved, the smaller 

 prints of the fore-limbs are also visible, showing 

 where the creature had progressed on all fours, just 

 as kangaroos do when feeding. The feet of the 

 gigantic Brontosaurus made an imprint covering 

 an area of a square yard ! In England, foot- 

 prints ascribed to Dinosaurs have also been 

 found. As Mr Lucas remarks, " oddly enough, 

 these numerous tracks all run one way, from 

 west to east, as if the animals were migrating, or 

 were pursuing well-known and customary routes 

 to their feeding-grounds." 



Whether these huge creatures laid eggs or 

 produced their young alive is a legitimate subject 

 for speculation. The probability is that they 

 were viviparous. In one species, indeed (Compso- 

 gnathus longipes), what appears to be the remains 

 of an embryo have been traced. 



In the matter of brains they seem to have 

 been singularly deficient, those of the very hugest 

 species not exceeding a weight of two pounds. 

 Much the same holds good with the giants among 

 the Mammalia, Really, however, there is no 

 need that the size of the brain should increase in 

 the same ratio as the size of the body. The 

 amount of intelligence required of these giants is 

 no greater than that demanded of their relatively 

 pygmy relations, and of co-ordination of move- 

 ment much the same may be said. It is only 

 when creatures of low intelligence come into 

 contact with more highly gifted competitors 

 that brain power tells, as witness the results 



