{354}What the jaws have got hold of is not allowed to escape again. The tortoise holds on and tears the prey to pieces with the sharp-clawed fingers. This takes a long time, only the scraped-off flesh and the intestines being eaten. The skeleton remains and sinks to the bottom, while in the case of a fish, the air-bladder floats away on the surface, and remains there as one of the surest signs of the existence of tortoises in that locality. The bones are cleaned with wonderful neatness. Some of my grass-snakes shared this fate, their backbones, with the hundreds of pairs of ribs, being picked or rather scraped clean, scarcely less well than if they had been prepared for a museum. As a rule the prey must be in motion to be seized, unless the tortoise has watched it before, and even then the latter prefers to smell it before biting. In captivity they soon learn to eat meat, and they become very tame, but in their native haunts they are extremely shy and cautious. Fond of basking upon a stone or on the banks, with the four limbs sprawling, or with the hind-limbs stretched backwards, and with the webs spread out so as to offer as large a surface as possible to the rays of the sun, they lie motionless for hours and appear fast asleep. But the slightest noise, or any other sign of our approach, is sufficient to send them plumping into the water, and to make them scuttle along with unsuspected agility. Nothing but the audible plump of the flat body and the widening rings of the disturbed water indicate their presence. After a long time of waiting we give it up, and turn away. That very instant we see a little ripple, caused by the withdrawing of the tortoise, which had come to the surface and had been watching us, with only the nose and eyes peeping out of the water, the rest being concealed between the floating vegetation. Apparently they cannot see us well with their eyes still under water, owing to the difference of refraction, otherwise they would not peep out and then at once turn back. It is certainly not for the want of air, since they can remain below for many hours without breathing.