378 THE TORTOISE. [chap. xvii. 



those islands where there is no water, or in the lower and 

 arid parts of the others, feed chiefly on the succulent cactus. 

 Those which frequent the higher and damp regions, eat the 

 leaves of various trees, a kind of berry (called guayavita) 

 which is acid and austere, and likewise a pale green fila- 

 mentous lichen {Usnera plicatd), that hangs in tresses from 

 the boughs of the trees. 



The tortoise is very fond of water, drinking large 

 quantities, and wallowing in the mud. The larger islands 

 alone possess springs, and these are always situated towards 

 the central parts, and at a considerable height. The tortoises, 

 therefore, which frequent the lower districts, when thirsty, are 

 obliged to travel from a long distance. Hence broad and 

 well-beaten paths branch off in every direction from the wells 

 down to the sea-coast ; and the Spaniards by following them 

 up, first discovered the watering-places. When I landed at 

 Chatham Island, I could not imagine what animal travelled 

 so methodically along well-chosen tracks. Near the springs 

 it was a curious spectacle to behold many of these huge 

 creatures, one set eagerly travelling onwards with out- 

 stretched necks, and another set returning, after having 

 dnmk their fill. When the tortoise arrives at the spring, 

 quite regardless of any spectator, he buries his head in the 

 water above his eyes, and greedily swallows great mouthfuls, 

 at the rate of about ten in a minute. The inhabitants say 

 each animal stays three or four days in the neighbourhood 

 of the water, and then returns to the lower country ; but 

 they differed respecting the frequency of these visits. The 

 animal probably regulates them according to the nature of 

 the food on which it has lived. It is, however, certain, that 

 tortoises can subsist even on those islands, where there is 

 no other water than what falls during a few rainy days in 

 the year. 



I believe it is well ascertained that the bladder of the frog 

 acts as a reservoir for the moisture necessary to its existence : 

 such seems to be the case with the tortoise. For some time 

 after a visit to the springs, their urinary bladders are dis- 

 tended with fluid, which is said gradually to decrease in 

 volume, and to become less pure. The inhabitants, when 

 walking in the lower district, and overcome with thirst, 

 often take advantage of this circumstance, and drink 

 the contents of the bladder if full ; in one I saw killed, 

 the fluid was quite limpid, and had only a very slightly 

 bitter taste. The inhabitants, however, always first drink 



