TORTOISES AND TURTLES. 37 



don, Albemarle, and Duncan Island harbour a 

 few survivors. 



Such is the lamentable history of these helpless 

 victims, as collected with infinite pains by Dr 

 Gunther some five years since. 



Isolated by the submergence of the lower 

 land, these tortoises were prevented from inter- 

 breeding and the swamping effect of intercrossing, 

 so that in time each group of islands, and in the 

 case of the Galapagos, almost every island came 

 to possess its own peculiar species. 



Of the many species of these Galapagos tor- 

 toises which have been described, two only can 

 be mentioned here. The first, and perhaps the 

 most interesting of all, is Daudin's Tortoise, 

 Testudo daudini, from the south island of Aldabra. 

 A specimen recently in the collection of the Hon. 

 Walter Eothschild was the largest living tortoise 

 known. The length of its shell was 55 inches, 

 or 67^- over the curve, and the weight 560 Ibs. 

 The species known as Testudo abingdoni is peculiar 

 on account of the thinness of its shell, which is 

 extremely delicate. A curious feature about the 

 carapace of these Galapagos tortoises, or at least 

 of the majority of the species, is the great size 

 of the opening of the front of the shell, which 

 presents a cave-like appearance, very different 

 from the narrow crescentic aperture of the typical 

 tortoise. 



Water is hard to find in the islands where 

 these tortoise live, and travellers have often 

 found relief for their parching thirst in the fluid 

 contained in the pericardium or membrane sur- 

 rounding the heart. The naturalist Baur relates 



