Bibliograjjliical Notice. 247 



wanting, however, descriptive pasaagea of considerable power and 

 truthfulness ; and many of the general observations and reflections 

 scattered throughout the work are instructive and sound. 



The mode in which 3Jr. Belt handles the subject of the glacial 

 epoch, and the influence it had upon the distribution of plants and 

 animals, may be selected as an illustration of the above remarks. 

 In the course of a journey he took to the mountainous district near 

 Ocotal, on the northern frontier of Nicaragua, he discovered an ex- 

 tensive deposit of unstratified gravel with boulders, which, he had 

 no doubt, formed the moraine of a huge glacier, at an altitude of not 

 more than 20U0 to 3000 feet above the present sea-level. The 

 deposit had been worn through by streams, in some places to the 

 depth of 200 feet, exposing numerous vertical sections ; and, with 

 the single exception of striated surfaces, he observed all the same 

 signs of glacial action which he had studied in AVales, Scotland, and 

 Nova Scotia. Reasoning from this and other evidence which he 

 adduces, he first states the grounds on which he thinks it must be 

 concluded that the phenomena were due to glacier ice and not to 

 icebergs ; and he then draws the inference that the whole of the 

 high land between the tropics must have been, during the glacial 

 epoch, covered with snow and ice. A similar conclusion, as is well 

 known, had been arrived at before bj' other writers ; but no one had 

 hitherto offered a satisfactory explanation of the non-extinction, in 

 that state of things, of the vast host of peculiar forms of plants and 

 animals still existing in the equatorial lowlands. Mr. Belt, in 

 accounting for this, adopts and extends an hypothesis of Mr. Alfred 

 Tylor, to the effect that the quantity of water locked up in the 

 polar ice-cap lowered the level of the sea to the extent of 600 feet. 

 He believes the depression would exceed 1000 feet, and that 

 the tracts of sea-bottom thereby laid bare would form a refuge 

 for the equatorial fauna and flora. The h}7)othesis is not fuUy 

 worked out ; and it would be necessary, before it can be seriously 

 dealt with, to explain the climatal conditions of the lowlands between 

 the tropics at a time when all the elevated land was subject to arctic 

 rigour. One obvious consideration he has certainly omitted to note, 

 \vi. that a lowering of the sea by 1000 feet would act on cUmate 

 chiefly by making all the land virtually 1000 feet higher, as the 

 atmosphere, being constant in total amount, would descend with the 

 lowering of the sea-level. This would produce a train of conse- 

 quences in a high degree favourable to the state of things Mr. Belt 

 supposes to have existed. 



With regard to its other effects on the distribution of plants and 

 animals, he ingeniously points out how the laying bare of shallow 

 seas, such as those separating Borneo and the neighbouring islands 

 from continental Asia, would account for the present existence of 

 so many species and genera of terrestrial animals in lands now 

 separated from each other. He goes, however, too far in reviving 

 the fabled Atlantis. Whatever we may think of this hj-pothesis in 

 the form too briefly sketched out by !Mr. Belt, there can bo no doubt 

 of its great suggestiveness, and of the justness of his view in requiring 



