336 The Naturalist in La Plata. 



to move or rest, and to act at all times harmoniously 

 together, as if controlled and guided by an extrane- 

 ous force. I may mention that the kindly instinct 

 in animals, which is almost universal between male 

 and female in the vertebrates, is most apparent in 

 these harmoniously acting birds. Thus, in La 

 Plata", I have remarked, in more than one species, 

 that a lame or sick individual, unable to keep pace 

 with the flock and find its food, has not only been 

 waited for, but in some cases some of the flock 

 have constantly attended it, keeping close to it 

 both when flying and on the ground ; and, I have 

 no doubt, feeding it just as they would have fed 

 their young. 



J^aturally among such kinds no one member is of 

 more consideration than another. But among mam- 

 mals such equality and harmonyis rare. The instinct 

 of one and all is to lord it over the others, with the 

 result that one more powerful or domineering gets 

 the mastery, to keep it thereafter as long as he can. 

 The lower animals are, in this respect, very much 

 like us; and in all kinds that are at all fierce- 

 tempered the mastery of one over all, and of a few 

 under him over the others, is most salutary ; 

 indeed, it is inconceivable that they should be able 

 to exist together under any other system. 



On cattle-breeding establishments on the pampas, 

 where it is usual to keep a large number of fierce- 

 tempered dogs, I have observed these animals a 

 great deal, and presume that they are very much 

 like feral dogs and wolves in their habits. Their 

 quarrels are incessant ; but when a fight begins 

 the head of the pack as a rule rushes to the 



