170 NATURAL HISTORY. 



tortoise-shell on the back, of a dull greenish-black colour; but the 

 surface is always covered with little chips coming off, which give it 

 a grey appearance when dry. When polished, it shows very pretty 

 markings. These shields are no thicker than a sheet of thick note- 

 paper, ; but the bony plates below them are sometimes as much as 

 a quarter of an inch thick on the sides and half an inch on the shoulders. 



The largest I ever got on this coast measured 5 feet between per- 

 pendiculars, with his head as far in as he could withdraw it. The 

 greatest total length may bo taken at 5 feet 6 inches, and the live weight 

 was 2601bs. avoirdupois. No doubt larger specimens occur; but from the 

 information of a friend who had paid special attention to Turtles at the 

 Nicobars (where they abound), 1 find that the average there is much 

 the same as here ; and anything over 1601bs. is a good Turtle. They 

 are frequently caught in nets ; and the females are surprised at 

 night when laying their eggs. For this purpose they prefer mid- 

 night and a spring high-tide, but are not strictly bound to time or 

 tide ; and I should not be surprised if they were found to lay in 

 broad daylight on uninhabited coasts. They crawl up above high 

 water-mark, often on grassy sand dunes several feet above it, and 

 dig a hole, which is usually about 15 inches deep. The eggs, about 

 125 (but often far more numerous), are laid in the hole and 

 covered with sand. They are at first of a very pale yellowish-pink 

 colour, rather less than a racket-ball ; and each egg has a crease in it. 

 As development goes on, this disappears ; the parchment-like skin of 

 the egg becomes tight, and perhaps even stretches a little ; at any 

 rate the whole egg looks larger, and a dark blue stain appears on 

 one side, the rest of the egg acquiring a dull white colour. 



The Natives say that the old Turtle knows when the eggs will hatch, 

 and then swims opposite the nest at high-water, and whistles ! to the 

 young, who, in obedience to the signal, tumble up out of the sand, 

 and scuttle down to the water. The period of hatching varies 

 greatly. The Natives put it at 3 weeks ; and I know from experiment 

 that this is sometimes enough. But I have now six clutches under 

 observation, of which two are 42 days # old and one 36 days. It 

 depends upon the position and weather ; shade and low temperatures 

 evidently retard the hatching. Both wet and drought can prevent it 

 altogether; the sand must bo damp enough to keep the eggs cool, but 

 well drained and, if possible, exposed to the full blaze of the sun. 

 lkeep most of the eggs in baskets, full of sand, set on bricks to secure 

 drainage, The young are amusing creatures, very black and very 



