224 



CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



green filamentous lichen ( Usnea plicata) that hangs in tresses 

 from the boughs of the trees. 



"The tortoise is very fond of water, drinking large quan- 

 tities and wallowing in the mud. The larger islands alone 

 possess springs, and these are always situated toward the cen- 

 tral parts, and at a considerable height. The tortoises, there- 

 fore, 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 Chat- 

 ham Island, I could not imagine what animal traveled so 

 methodically along well-chosen tracks. Near the springs it 

 was a curious spectacle to behold many of these huge creat- 

 ures, one set eagerly traveling onward with outstretched necks, 

 and another set returning, after having drunk their fill. When 

 the tortoise arrives at the spring, quite regardless of any spec- 

 tator, 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 neighborhood 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 he has lived. It is, how- 

 ever, 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 vol- 

 ume, 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 the water in the pericardium, 

 which is described as being best. 



