34 WHAT MR. DARWIN SAW. 



URUGUAY. 



ject of affection. I believe I am right, however, in saying 

 that any animal with a bell will serve as a madrina). In a 

 troop, each animal carries, on a level road, a cargo weighing 

 four hundred and sixteen pounds, but in a mountainous coun- 

 try one hundred pounds less; yet with what delicate, slim 

 limbs, without any proportional bulk of muscle, these animals 

 support so great a burden ! The mule always appears to me 

 a most surprising animal. That the offspring of the horse 

 and the ass should possess more reason, memory, obstinacy, 

 social affection, powers of muscular endurance, and length 

 of life, than either of its parents, seems to indicate that art 

 has here outdone nature. 



THE OX. 



THE chief trouble with an estancia (grazing farm) is 

 driving the cattle twice a week to a central spot, in order 

 to make them tame and to count them. This latter opera- 

 tion would be thought difficult where there are ten or fif- 

 teen thousand head together. It is managed on the princi- 

 ple that the cattle invariably divide themselves into little 

 troops (tropillas) of from forty to a hundred. Each troop 

 is recognized by a few peculiarly marked animals, and its 

 number is known ; so that, one being lost out of ten thou- 

 sand, it is perceived by its absence from one of the tropi- 

 llas. During a stormy night the cattle all mingle together, 

 but the next morning the tropillas separate as before; so 

 that each animal must know its fellow out of ten thousand 

 others. 



