THE BRITISH NATURALIST. 



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and achieve their object of providing a comfortable dwelling which 

 shall protect its occupants from the weather and from their 

 carnivorous foes. Beavers also sometimes unite to construct 

 dams, which, by raising the level of the water round their 

 homes, give increased protection, and the skill with which these little 

 animals — about a foot high and not much more than a yard long, in- 

 cluding the tail — pile up large logs, stones, and mud is really 

 marvellous. There can be little doubt that the improvement of the 

 social instincts and of the general intelligence in this species are cor- 

 related ; those individuals, or at least the majority of those, which were 

 not social would be eliminated by natural selection ; the social 

 individuals on the other hand — and every increase in social sentiment 

 and in skill in adapting themselves and their dwellings to local circum- 

 stances would accentuate this superiority — had only one other animal 

 to fear, man. Before this competitor they are now disappearing, for he 

 cannot afford to see valuable forests of timber trees destroyed and the 

 climate of large tracts of country altered, even though the alternative 

 be the destruction of the most social Rodent, and one of the most 

 intelligent of all animals ; so he ruthlessly breaks down both lodge and 

 dam, and the place which once knew the beaver knows it no more. 



Passing to the order Ungulata, we find that the majority of the 

 species live in herds; especially amongst the ruminants is this gregarious 

 instinct well marked. The same deep-seated constitutional tendency 

 manifests itself in both the muscular, nervous, and digestive systems of 

 these animals. The power to eat rapidly large quantities of vegetable 

 food, which can be subsequently re-gurgitated and chewed at leisure ; 

 the tendency to seek safety in speedy flight rather than by attempting 

 to resist attack, and the habit of living in flocks whose individuals warn 

 one another of a common peril, and in the last resource often unite to 

 resist a common enemy, are characteristic features of the Ruminants. 

 Since polygamy is common amongst them, it may well be that the 

 polygamous family is the primitive social unit amongst these animals ; 

 but it is impossible to be certain on this point, for some live in pairs, and 

 the gregarious instinct may in some cases have had its origin from rapid 

 multiplication of individuals on areas yielding abundant food, and from 

 the subsequent union of such individuals to resist beasts of prey, to 

 whom stragglers fell easy victims. Natural selection would foster the 

 gregarious instinct amongst such animals, whatever the nature of their 

 sexual unions, whether promiscuous, polygamous, or monogamous. 



Gregariousness is, however, at best a very low form of sociality, nor 

 can much be said in favour of either the intelligence or the sociability 

 of many ruminants, which in suitable localities occur in immense 

 droves. Several species of South African antelopes formerly occurred 

 in immense numbers, yet though many of them are beautiful they are 



