THE ELEPHANTINE TORTOISE. 323 



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 tlie 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, and arrive at their journey's end much 

 sooner than would be expected. The inhabitants, from obser- 

 vations 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, and it is said to recover soon from this strange opera- 

 tion. 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 flatteued 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 

 them, instantly withdrew their head and legs, and fell flat 



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