GREAT TORTOISE. 153 



diftered respecting the frequency of tliese 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 ne- 

 cessary to its existence : such seems to be the case 

 with the tortoise. For some lime after a visit to 

 the springs, their urinary bladders are distended 

 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 circum- 

 stance, 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 in- 

 habitants, however, always first drink the water in 

 the pericardium, which is described as being best. 



The tortoises, when purposely moving towards 

 any point, travel by night and day, and arrive at 

 their journey's end much sooner than would be 

 expected. The inhabitants, from observing marked 

 individuals, consider that they travel a distance of 

 about eight miles in two or three days. One large 

 tortoise, which I watched, walked at the rate of 

 sixty yards in ten minutes, that is 360 yards in the 

 hour, or four miles a day, allowing a little time for 

 it to eat on the road. During the breeding season, 

 when the male and female are together, the male 

 utters a hoarse roar or bellowing, which, it is said, 

 can be heard at the distance of more than a hun- 

 dred yards. The female never uses her voice, and 

 the male only at these times ; so that when the 

 people hear this noise, they know that the two are 

 together. Thev were at this time (October) laying 



