GREAT STEPS IN ORGANIC EVOLUTION 893 



England and Scotland. This was one of the earliest injustices to 

 Ireland. Thus there is no evidence that Ireland ever received the 

 mole or the common hare ; and her pleasing myth as to the banish- 

 ment of snakes must, we fear, in time give place to this earlier line 

 of explanation. 



The next chapter extends till to-day, and it is from the natural 

 history point of view a sad story of losses. Man}^ mammals that were 

 British at the time of insulation have disappeared entirely, and 

 other kinds are disappearing now. We have entirely lost the reindeer, 

 the giant Irish deer, the bear, the wolf, the beaver, the lemming, 

 and the interesting desman. We are losing the pine-marten, the 

 pole-cat, the wild-cat, and the badger. Apart from bats and seals 

 and cetaceans, there are only twenty-five British mammals to-day. 



Fig. 154. 



Antlers of the Extinct Giant Irish Deer, Cervus megaceros. From a specimen. 

 Illustrating exaggerated, perhaps even fatal, sex-hormonised growth. 

 The spread of the antlers may reach to ten feet, and the weight to 

 eighty pounds. 



What are the reasons for the disappearance and the dwindling? 

 (i) In a restricted area keen competition may result in extermina- 

 tion. Thus the wolves probably helped in the destruction of the 

 reindeer. (2) It is possible that the amelioration of the climate went 

 too far for some types, which had to leave the milder low grounds 

 and become refugees on the mountains. Thus the Mountain Hare, 

 though very abundant in some parts of the Highlands, has a 

 restricted range to-day compared with what it once had. (3) In 

 the strange case of the giant Irish deer, it seems probable that the 

 creature was its own doom by becoming over-specialised in its 

 antlers. These sometimes had a spread of ten feet and a weight of 

 eighty pounds; and the stags had to grow them afresh each year. 

 It is quite possible for an animal to have too much of a good thing. 

 (4) But the chief cause of disappearance and dwindling was man. 

 He hunted some of the mammals, such as reindeer and wild cattle, 



