GIANT TORTOISES AND THEIR DISTRIBUTION 303 



of the Siwalik Hills of North-western India, more fully referred 

 to later. The aforesaid living African species is, however, of 

 a light brownish yellov/ colour thereby differing markedly 

 from all the modern insular giant tortoises, which, in addition 

 to the length of their necks, are collectively characterised by 

 their uniformly dark brown or black coloration. Whether the 

 same funereal tint characterising the living species also obtained 

 in the extinct Siwalik species cannot, of course, be determined ; 

 although from the similarity of its shell to that of the living 

 T. calcarata it is quite probable that this was not the case. Other 

 extinct tortoises, however, have shells more like those of the 

 modern insular forms, with which they may therefore have 

 agreed in colouring. 



In modern times, that is to say during the historic and 

 immediately preceding periods, giant tortoises, so far as can be 

 ascertained, have been restricted to the Galapagos (Tortoise) 

 Islands, situated on and immediately south of the equator, 

 ten degrees west of the coast of Equador, in the South 

 Pacific, and in the Indian Ocean to Madagascar, probably the 

 Comoros, North and South Aldabra — small islands lying to 

 the north-west of the northern point of Madagascar — the 

 Mascarenes or Mascarenhas, situated to the east of Mada- 

 gascar, and including Reunion, Mauritius and Rodriguez, and 

 lastly the Amirantes and the Seychelles, which are the most 

 northern of the whole assemblage, and only about four degrees 

 south of the equator. The whole group is thus confined at the 

 present day to the southern hemisphere. 



From Madagascar the tortoises disappeared before the island 

 was explored by naturalists ; in the other islands of the 

 Indian Ocean, as in those of the Galapagos group, most of the 

 species survived till a very recent date and were in many 

 instances abundant less than a century ago, as indeed some of 

 them are in the Galapagos at the present day. 



With the exception of Madagascar, where there were two 

 probably contemporary species of hippopotamus, to say nothing 

 of a small existing bush-pig and the half cat-like, half civet-like 

 carnivore known as the fossa, the islands inhabited by modern 

 giant tortoises were free from mammals of large size ; and it has 

 been suggested that this freedom from competition with the 

 higher forms of life has been one, if not the chief, of the reasons 

 why these sluggish reptiles should have survived and flourished 



