390 ORGANISATIONS. 



of strangers ' (Tinne). Ant guards open and shut gates and 

 awaken sleepers (Huber). 



Spies or scouts are employed by various animals, in- 

 cluding the elephant (Watson and Houzeau) and the wild 

 horse, the swallow ('Percy Anecdotes') and the loxia (another 

 bird) (Pierquin), and the ant (Figuier). These scouts have 

 to make investigations and reports ; in the case of the ele- 

 phant, for instance, they have to look out for pitfalls (Hou- 

 zeau). Hence it is that, as in the case of sentinels, old, 

 experienced, sagacious, cautious, observant animals are se- 

 lected. 



Illustrations of a very different kind of successful playing 

 a part are to be found in the various performances of trained 

 animals in the theatrical, musical, or other exhibitions in 

 which dogs, cats, pigs, horses, and various birds, such as the 

 canary, goldfinch, and linnet, are among the artists. 



Some of the best illustrations of an adapted division of 



labour occur in connection with the important phenomena 



of co-operation of preconcerted action for a common end or 



object. In a great variety of ways many of the lower animals 



recognise and act upon the principle that union is, or gives, 



strength. They form combinations, associations, or alliances, 



temporary or permanent, for a great number of very specific 



purposes. They co-operate willingly, intelligently, and 



successfully not only with each other but with man. One 



of the most obvious effects of union is the inspiration of 



courage and confidence, the ability to dare and do, in behalf 



of themselves or their young, things that they would never 



attempt in their individual capacities. Even timid sheep, 



in combination in a body, and under a leader, do boldly 



what they would never do individually face a dog, for 



instance, or even chase it ignominiously from a field or 



pasture. The meek cow and many gentle, peace-loving 



birds are capable of the same feats of courage under similar 



circumstances. 



The simplest forms of co-operation with each other are 

 those in which only two individuals are engaged, though 

 these two frequently belong to different species, genera, and 

 even orders or classes. And in such cases the assignation 

 by mutual agreement after consultation of a special duty to 



