46 Mr. Henry Walker's Lecture : 



oxen of colossal size were selected and established ; the 

 enormous ** Irish elk" was supreme among the cervidae of 

 the period, and other giant animals were on their way to 

 these western feeding grounds and fastnesses. The land had 

 recovered from the depopulation, extinction, and wreck of 

 the great submergence, and the glaciation which succeeded. 

 The great Europasiau invasion had begun. 



THE SOUTHEEN AND SUB-TROPICAL ANIMALS. 



We have thus far accounted for the presence of the 

 northern and Arctic group of animals found fossil at Ilford. 

 We have seen the remarkable geographical surroundings 

 amid which they lived, and we may see all around us in 

 Essex the surviving memorials of the climate of the 

 mammoth, and the woolly rhinoceros. The problem pre- 

 sented by the southern and sub-tropical fauna still remains 

 to be considered. 



This group of the Ilford fauna consists of the lion, two 

 rhinoceroses (the " leptorhine," or small-nosed, and the 

 "megarhine," or big-nosed), the straight-tusked elephant, 

 the hippopotamus, and the little river mollusk, Cyrena 

 fluminalis. 



Of this strange collection of British Pleistocene mam- 

 malia, the Elephas antiquus and the two rhinoceroses are 

 now extinct. The hippopotamus, which in Pleistocene 

 times ranged as far as Yorkshire and has been found in 

 valleys near Leeds, is not now found north of the Nile ; 



Britain" (Glasgow Science Series, 1878-9). At page 15, the lecturer 

 remarks: — "Modern civilisation, by extirpating beasts of prey, lias 

 rendered it possible for us to leave herds and flocks of small oxen and 

 sheep out in the open. In times of ancient savagery, in which packs 

 of wolves held their own, none but big animals would be so left. In 

 those times also, the country was not mapped out by ' formal props of 

 restless ownership,' and these wild animals had a much wider range, 

 and having better pasturage grew larger accordingly. It is clear that 

 both causes — the presence of wild carnivora, and the absence of en- 

 closures — must have co-operated in increasing the size of the 

 graminivorous beasts. Tlwse cattle were large because, if a small bull 

 encountered a pack, lioioever small, of loolves, it was pulled down, and there 

 was an end of its existence, and of the chance which it had of propagating 

 small animals like itself.''^ 



