338 The Naturalist in La Plata. 



in the herd that he may be buffeted with impunity by 

 all, even by those that have hitherto suffered buffets 

 but have given none. But judging from my own 

 observation, this persecution is not, as a rule, 

 severe, and is seldom fatal. 



It is often the case that a sick or injured animal 

 withdraws and hides himself from the herd; the 

 instinct of the " stricken deer " this might be called.. 

 But I do not think that we need assume that the 

 ailing individual goes away to escape the danger of 

 being ill-used by his companions. He is sick and 

 drooping and consequently unfit to be with the 

 healthy and vigorous ; that is the simplest and 

 probably the true explanation of his action ; although 

 in some cases he might be driven from them by 

 persistent rough usage. However peaceably gre- 

 garious mammals may live together, and however 

 fond of each other's company they may be, they do 

 not, as a rule, treat each other gently. Further- 

 more, their games are exceedingly rough and require 

 that they shall be in a vigorous state of health to 

 escape injury. Horned animals have no buttons to 

 the sharp weapons they prod and strike each other 

 with in a sportive spirit. I have often witnessed 

 the games of wild and half- wild horses with astonish- 

 ment ; for it seemed that broken bones must result 

 from the sounding kicks they freely bestowed on one 

 another. This roughness itself would be a sufficient 

 cause for the action of the individual, sick and out 

 of tune and untouched by the glad contagion of the 

 others, in escaping from them; and to leave them 

 would be to its advantage (and to that of the race) 

 since, if not fatally injured or sick unto death, its 



