INTRODUCTION. XXXV11 



Syria and Hindostan ; the Bactrian Camel typifies the 

 huge Merycotherium of the Siberian drift ; the Elephant 

 and Rhinoceros are still represented in Asia, though now 

 confined to the south of the Himalayas. The true Ma- 

 cacques are peculiar to Asia, and, though most abundant 

 in the southern parts of the continent and the Indian 

 Archipelago, also exist in Japan ; a closely allied subgenus 

 (Inuus,) is naturalised on the rock of Gibraltar at the 

 present day. A fossil species of Macacus was associated 

 with the Elephant and Rhinoceros in England during the 

 period of the deposition of the newer pliocene fresh-water 

 beds.* The more extraordinary extinct forms of Mam- 

 malia called Elasmotherium and Sivatherium, have their 

 nearest existing pachydermal and ruminant analogues in 

 the same continent to which those fossils are peculiar. 

 Cuvier places the Elasmothere between the Horse and 

 Rhinoceros : the existing four-horned Antelopes, like their 

 gigantic extinct analogues, the Sivathere and Bramathere, 

 are peculiar to India. 



The Mediterranean and Red Seas constitute a less 

 artificial boundary between Africa and the Europseo- 

 Asiatic continent, than that which, on our maps, divides 

 Europe from Asia ; yet those narrow seas form a slight 

 demarcation as compared with the vast oceans which 

 divide the old from the new worlds of the geographer, 

 or these from the Australian continents. The continuity 

 of Africa with Asia is still, indeed, preserved by a narrow 

 isthmus, near to which, within the historical period, the 

 Hippopotamus descended, venturing down the Nile almost 

 to its mouth. May it not be regarded, then, as part of the 

 same general concordance of geographical distribution, that 



* See ' Comptes Rendus <le 1'Academie des Sciences,' Paris, Sept. 1:845, p. 

 573, and fig. 1, 2, 3, p. xliv. 



