120 LIFE : OUTLINES OF GENERAL BIOLOGY 



Animate Nature is illustrated by the fact that the post-nectar-dance 

 differs in some features from the post-pollen-diuice. 



6. It is interesting to inquire in detail into the advantages of the 

 social or corporate way of living. It is interesting from the ecological 

 or Natural History jxiint of view, for the advantages illumine such 

 achievements as the firmly built termitary, six feet high, with its 

 many nxmis and jxissages, the j^ossibility of such undertakings 

 as the Ix'avers" dam, and the intricacy of the inter-relations between 

 ants and other forms of life — both plants and animals. The inquiry 

 into advantages is al.so interesting biologically, for it reveals the 

 multitude of ways in which variations from the solitary mode of 

 life towards the social might be seized upon and utilised by natural 

 selection. And thirdly, the nquiry is interesting because it is sugges- 

 tive in relation to human affairs. Animate Nature has been for 

 hundreds of millions of years a vast experimental laboratory, 

 whose results are at times for our warning, yet also, it may be, for 

 our inspiration. No one proposes to argue from pismires to parlia- 

 ments, or from mice to men, but he who runs may read from the 

 study of social animals that for certain ends the co-operative or 

 comnumal way of living is likely to be more successful than that 

 which adliere^ to the "each for himself" policy. And with advantages 

 there go dangers, to be separately discu.ssed, which are luridly 

 illustrated by the seamy side of the much admired, and in many 

 ways most admirable beehive and ant-hill. Let us consider, then, 

 in some detail, how the social habit has justified itself in the struggle 

 for existence. 



(I) The most obvious advantage of the social habit is in the 

 strength that union gives. Individually, the ant is contemptible, 

 but a raid of driver-ants may be a terror; and the harm done within 

 recent years in Madeira by the invasion of the Argentine ant gives 

 a striking diagram of the practical results of such concerted action. 

 Small animals gain safety in combination; thus the fact that the 

 small .sand-martins are but little molested is partly explained by their 

 large numlxTs. Birds that are individually insignificant may combine 

 to "mob" a hawk, or an owl, or a cuckoo. Kropotkin pointed out long 

 ago in his Mutual Aid that a small monkey has no chance against 

 an eagle; yet the as.sailant bird may come off badly when the mon- 

 key's cries bring its comrades to its aid. There are, of course, many 

 gradations Ix^tween the sheer force of numbers and a unanimous 

 combination in attacking or repulsing an intruding enemy. 



(II) Slightly different is the increase in efTiciency which is some- 

 times attained by combined effort. A familiar instance is the 

 co-operation of several ants in the tran.sport of booty, such as a big 

 spider, which an individual cannot do more than move. A common 

 sight in some tropical countries is the combination of eight or more 

 tailor-ants in drawing two leaves together to form the beginning of 



