THE REPTILES 249 



developed. The " tortoiseshell," which is the ornamental horny 

 covering of the carapace and plastron, and out of which hair- 

 combs and other articles are manufactured, is to all intents and 

 purposes an outside or " scarf-skin " structure belonging to the 

 epidermis. It is in the form of thin plates, which are united 

 together at their edges, and which correspond to a certain extent 

 only with the underlying bones of the buckler. 



The eggs of the Land and Fresh-water Tortoises are of a cal- 

 careous nature outside, but those of the Turtle are leathery or 

 parchment-like to the touch. The egg-producing organ is very 

 similar to that of birds, and the internal structure of the egg and 

 the development of the young in its early stage differ in no very 

 essential circumstances from those of the bird. Both carapace 

 and plastron are formed before the young break out from the 



egg- 



Truly wonderful are the Giant Land Tortoises inhabiting the 

 Galapagos Islands, and it seems a sad pity that they are probably 

 doomed to total extinction in a few more years. Darwin in his 

 " Journal of the Voyage of the Beagle " gives a most deeply 

 interesting account of these gigantic reptiles. He states that 

 the old males are the largest, the females rarely growing to so 

 great a size, and that " 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 hundred yards. The female never uses her voice, and the 

 male only at these times." Of the water-drinking habits of this 

 tortoise, he writes : " The tortoise is very fond of water, drinking 

 large quantities, and wallowing in the mud. The larger islands 

 alone possess springs, and these are always situated towards the 

 central 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 seacoast ; 

 and the Spaniards, by following them up, first discovered the 

 watering-places. When I landed at Chatham Island I could not 

 imagine what animal travelled so methodically along well-chosen 

 tracks. Near the springs it was a curious spectacle to behold 

 many of these huge creatures, one set eagerly travelling onwards 

 with outstretched necks, and another set returning, after having 



