2G8 THE NATURALIST IN NICARAGUA. [Cli. XIV. 



tion, reaching over at least five degrees of latitude, 

 between the north of British Guiana and Barbados ; 

 and may freely indulge in the dream that the waters of 

 the Orinoco, when they ran over the lowlands of Trini- 

 dad, passed east of Tobago, then northward between 

 Barbados and St. Lucia, afterwards turning westward 

 between the latter island and Martinique, and that the 

 mighty estuary for a great part at least of that line 

 formed the original barrier which kept the land shells of 

 Venezuela apart from those of Guiana."* 



A very similar theory has been propounded by Mr. 

 Wallace to account for the distribution of the faunas of 

 the Malay Archipelago in his admirable work on the 

 natural history of that region. f Java, Sumatra, and 

 Borneo are separated from each other, and from the 

 continent of Asia, by a shallow sea less than six hundred 

 feet in depth, and must at one time have been connected 

 by continuous land to allow of the elephant and tapir of 

 Sumatra and Borneo, the rhinoceros of Sumatra and 

 Java, and the wild cattle of Borneo and Java, to spread 

 from the continent to these now sea-surrounded lands, as 

 none of these large animals could have passed over the 

 arms of the sea that now separate them. The smaller 

 mammals, the birds, and insects, all illustrate this view, 

 almost all the genera found in any of the islands oc- 

 curring also on the Asiatic continent, and the species 

 being often identical. On the other hand, the fauna of 

 islands to the eastward are more closely connected with 

 Australia, and must at one time have been joined to it by 

 nearly continuous land. Honeysuckers and lories take 



* LOG. cit., p. 306. 



f " The Malay Archipelago," vol. i. p. 11. 



