126 SAUEIANS. 



one for a long time," continues Mr. Darwin, " till half of its body 

 was buried ; I then walked up and pulled it by the tail ; at this 

 it was greatly astonished, and soon shuffled up to see what was the 

 matter ; and then stared me in the face, as much as to say, ' What 

 made you pull my tail ? ' They feed by day, and do not wander 

 far from their burrows ; and, if frightened, they rush to them with 

 a most awkward gait. Except when running downhill, they 

 cannot move very fast ; which appears chiefly owing to the lateral 

 position of their legs. They are not at all timorous ; when atten- 

 tively watching any one, they curl up their tails, and raising them- 

 selves on their front legs, nod their head vertically, with a quick 

 movement, and try to look very fierce, but in reality they are not 

 at all so ; if one just stamps the ground, down go their tails, and 

 off they shuffle as quickly as they can. I have several times 

 observed small fly-eating Lizards, when watching anything, nod 

 their heads in precisely the same manner ; but I do not at all 

 know for what purpose. If the Amblyrhynchus is held, and 

 plagued with a stick, it will bite it very severely ; but I caught 

 many by the tail, and they never tried to bite me. If two are 

 placed on the ground, and held together, they will fight and bite 

 each other till blood is drawn. Those individuals (and they are 

 the greater number) which inhabit the lower country, can scarcely 

 taste a drop of water throughout the year ; but they consume 

 much of the succulent cactus, the branches of which are occa- 

 sionally broken- off by the wind. I have sometimes thrown a 

 piece to two or three when together ; and it was amusing enough 

 to see each trying to seize and carry it away in its mouth, like so 

 many hungry Dogs with a bone. They eat very deliberately, but 

 do not chew their food. The little birds are aware how harmless 

 these creatures are : I have seen one of the thick -billed Finches 

 (peculiar to the Grallapagos) picking at one end of a piece of cactus 

 which is in request among all the animals of the lower region 

 whilst a Lizard was eating at the other ; and afterwards the little 

 bird, with the utmost indifference, hopped on the back of the 

 reptile. The stomachs of several that I opened were full of 

 vegetable fibres and leaves of different trees, especially of a species 

 of Acacia. In the upper region they live chiefly on the acid and 

 astringent berries of the guayavita, under which trees I have seen 



