THE ELEPHANTINE TORTOISE 341 



country ; but they differed in their accounts respecting the fre- 

 quency of these visits. The animal probably regulates them 

 according to the nature of the food which it has consumed. 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, the urinary 

 bladder of these animals is distended with fluid, which is said 

 gradually to decrease in volume, and to become less pure. The 

 inhabitants, when walking in the lower districts and overcome 

 with thirst, often take advantage of this circumstance by killing 

 a tortoise, and if the bladder is full, drinking its contents. In 

 one I saw killed, the fluid was quite limpid, and had only a very 

 slightly bitter taste. 



" The tortoises, when moving towards any definite point, travel 

 by night and day, &,nd arrive at their journey's end much sooner 

 than would be expected. The inhabitants, from observations 

 on marked individuals, consider that they can move a distance 

 of about eight miles in two or three days. One large tortoise, 

 ■ which I watched, I found walked at the rate of sixty yards 

 in ten minutes, that is, three hundred and sixty in the hour, 

 or four miles a day, allowing also a little time for it to eat on 

 the road. The flesh of this animal is largely employed, both 

 fresh and salted, and a beautifully clear oil is prepared from 

 the fat. 



" When a tortoise is caught, the man makes a slit in the skin 

 near its tail, so as to see inside its body, whether the fat under 

 the dorsal plate is thick. If it is not, the animal is liberated, 

 iind it is said to recover soon from this strange operation. In 

 order to secure the tortoises, it is not sufficient to turn them like 

 turtle (their upper buckler being highly arched, while it is more 

 flattened in the aquatic families, for the better adaptation of 

 their forms to motion in a liquid), for they are often able to 

 regain their upright position." 



They are said to be completely deaf; so much is certain, that 

 they do not perceive a person even when walking close behind 

 them. Mr. Darwin often amused himself by overtaking the 

 slow and monstrous creatures, who, as soon as he had passed 



