MILITARY TACTICS OF ANIMALS 53 



There are some exceptions to the general smoothness 

 which marks the evolutions of these animal regiments 

 and army corps ; the blind rush of the migrating 

 bison has been known to force thousands into the 

 bottomless mud of American rivers, and the swarms 

 of lemmings are said to march into the sea. But, 

 as a rule,' herds of antelopes, of deer, or even flocks 

 of mountain sheep, will travel for days without 

 disaster, arriving simultaneously at the point desired, 

 and * keeping distance/ that great difficulty of the 

 march, throughout the journey. A large herd of 

 deer will gather in column, or break into file, and 

 disappear through a mountain pass in less time than 

 the same number of trained troopers would take to 

 ' form fours ; ' and a flock of half-wild sheep on 

 a Yorkshire moor will assemble, descend into the 

 valley, cross a river in single file, and form upon the 

 opposite bank without a false movement by any one 

 of their number. The military precision with which 

 flocks of birds wheel or advance is even more re- 

 markable, because, in the case of some birds at least, 

 a regular geometrical formation is always observed. 

 Wild geese, wild ducks, and their relations adopt 

 the V formation ; and not only adhere to this, with 

 certain modifications to suit circumstances, but also 

 to a regular scale of distances between the different 

 birds in the flock, so closely, that we are forced to 



