THE VOYAGE OF THE BEAGLE 163 



gravel on the sea-beach. Each crystal was about five lines 

 in diameter, and from an inch to an inch and a half in 

 length. Many of them had a small canal extending from 

 one extremity to the other, perfectly cylindrical, and of a 

 size that readily admitted a coarse thread or a piece of fine 

 catgut. Their colour was red or dull white. The natives 

 were acquainted with this structure in crystals. I have 

 mentioned these circumstances because, although no crystal- 

 lized body is at present known to assume this form, it may 

 lead some future traveller to investigate the real nature of 

 such stones. 



While staying at this estancia, I was amused with what 

 I saw and heard of the shepherd-dogs of the country. 3 When 

 riding, it is a common thing to meet a large flock of sheep 

 guarded by one or two dogs, at the distance of some miles 

 from any house or man. I often wondered how so firm a 

 friendship had been established. The method of education 

 consists in separating the puppy, while very young, from 

 the bitch, and in accustoming it to its future companions. 

 An ewe is held three or four times a day for the little thing 

 to suck, and a nest of wool is made for it in the sheep-pen ; 

 at no time is it allowed to associate with other dogs, or with 

 the children of the family. The puppy is, moreover, gen- 

 erally castrated; so that, when grown up, it can scarcely 

 have any feelings in common with the rest of its kind. From 

 this education it has no wish to leave the flock, and just 

 as another dog will defend its master, man, so will these 

 the sheep. It is amusing to observe, when approaching a 

 flock, how the dog immediately advances barking, and the 

 sheep all close in his rear, as if round the oldest ram. These 

 dogs are also easily taught to bring home the flock, at a 

 certain hour in the evening. Their most troublesome fault, 

 when young, is their desire of playing with the sheep; for 

 in their sport they sometimes gallop their poor subjects most 

 unmercifully. 



The shepherd-dog comes to the house every day for some 

 meat, and as soon as it is given him, he skulks away as if 



3 M. A. d'Orbigny has given nearly a similar account of these dogs, 

 torn. i. p. 175. 



