392 OEGANISATIONS. 



Two taine ravens plundered a bird trap the one lifting 

 up the lid, the other removing the captured bird (Wood). 

 In another case a wolf drove a herd of gazelles to a ravine 

 in which two of its comrades were concealed in ambush. 

 In a third instance different posts as to the locality to be 

 occupied were allotted to each of a pack of six wolves that 

 co-operated to entrap a herd of Indian antelopes. 



Co-operation on a large scale on the part of large num- 

 bers of individuals, whether of the same or of different 

 species and genera includes the convention, at special 

 times and places, of convocations, conferences, congrega- 

 tions, or assemblies for the following or other specific ends : 



1. Judicial for the trial and punishment of offenders. 



2. Military for the holding of councils of war. 



3. Recreational for the celebration of pastimes, sports, 

 or games of various kinds. 



4. Migrational for conference as to the time and man- 

 ner of migration. 



5. Defensive for mutual protection, security or safety. 



6. Industrial for the repair of damage to public pro- 

 perty. 



7. Marauding for the acquisition of plunder or booty. 



8. Food-seeking or foraging. 



9. Emigration and colonisation. 



10. Nuptial for courtship and marriage. 



11. Hybernation. 



12. Criminal as for theft. 



13. The rescue of their fellows from captivity or danger. 

 One of the most interesting features of co-operation 



among the lower animals is rotation of duty or privilege 

 the taking by turn work, food, or drink. In drinking, various 

 sand-grouse of South Africa (species of Pterocles and Ptero- 

 churus) ' do not rush simultaneously to the pool, but each 

 one waits its turn, the first comers having the precedence.' 

 The same is the case with the pintado or wild Guinea fowl 

 of Damara and Namaqua Land, the large flocks of which, on 

 approaching water, ' go to work most systematically,' so that 

 all may have in turn access (Andersson). In the same way 

 wild geese and ducks, starlings and other birds, take turns 



