1574 THE STORY OF THE UNIVERSE 



plained: the field was covered with rooks; the origi- 

 nal assemblage had been calling together a mouse- 

 hunt, which could only be successfully carried out 

 by a large number of birds acting in conjunction. 

 By diligently probing the ground and blocking up 

 the network of runs, the voles, one or more at a time, 

 were gradually driven into a corner. The hunt was 

 very successful, and no more voles were seen in that 

 field during the winter. 



Other animals are not easily discouraged by the 

 swiftness of their prey; they count on their own re- 

 sistance in order to tire the game; some of them also 

 manage their pursuit in the most intelligent way, so 

 as to preserve their own strength while the tracked 

 animal's strength goes on diminishing until exhaus- 

 tion and fatigue place him at their mercy. 



Mammals especially, such as dogs, wolves, and 

 foxes, exercise this kind of chase; it is, exactly, the 

 coursing which man has merely had to direct for his 

 own benefit. Wild dogs pursue their prey united in 

 immense packs. They excite each other by barking 

 while they frighten the game and half paralyze his 

 efforts. No animal is agile and strong enough to be 

 sure of escaping. They surround him and cut off his 

 retreat in a most skilful manner; gazelles and ante- 

 lopes, in spite of their extreme nimbleness and speed, 

 are caught at last; boars are rapidly driven into a 

 corner; their vigorous defence may cost the life of 

 some of the assailants, but they nevertheless become 

 the prey of the band who rush on to the quarry. In 

 Asia wild dogs do not fear even to attack the tiger. 



Wolves hunt also in considerable bands. Their au- 



