5M 



NA TURE 



[Ai'RiL 3, 1902 



mean altitude of from 2000 to 3000 feet above the sea, 

 the central uplands, including the Atlantic slopes of the 

 Nicaraguan backbone, enjoy a relatively mild climate, 

 generally healthy and suited for European settlement." 

 Of Costa Rica, "probably 275,000, out of a total popula- 

 tion of 294,000, have already been fused in a somewhat 

 homogeneous Ladinn element of Spanish speech and 

 culture. As in Salvador and Nicaragua, the people are 

 concentrated in the fertile and salubrious volcanic 

 districts on the Pacific slope." Mr. Keane's description 

 of the principal West Indian islands is admirable and 

 varied, and enables the reader to understand their im- 

 portance in the general movement of the world ; but the 

 voluminous publications of the United Stales (",overn- 

 ment, in 1900, relative to Cuba and Puerlorico, might 

 have been consulted with advantage. Saving the defect 

 that much of the industrial, financial and commercial data 

 are not brought up to date, the volume is an extremely 

 useful and instructive compendium of the subjects of 

 which it treats, and does great credit both to the publisher 

 and the author. One of the illustrations is reproduced on 

 the preceding page. George E.ari, Church. 



THE MALDIVE AND LACCADIVE 

 ARCHIPELAGOES?- 



FEW oceanic island groups are of greater interest to 

 the students of the science of "distribution" than 

 the Laccadives, Maldives, Chagos and Seychelles, since 

 they appear to be the last remnants of a land connection 

 between India and Madagascar. For in- 

 stance. Dr. W. T. Blanford, in his presi- 

 dential address to the Geological Society 

 for 1890, after mentioning that there ap- 

 peared to be evidence of deep water 

 between the banks on which the above- 

 mentioned islands are situated, proceeded 

 to say that he believed a fuller knowledge 

 of the contours would reveal the existence 

 of a bank connecting the whole series from 

 India to Madagascar. " Even should this 

 not be case, the evidence of a land- 

 connection appears so strong that it may be 

 a question whether the whole of the ocean- 

 bottom between Africa and India may not 

 have sunk to its present depth since Creta- 

 ceous times." 



In addition to this special point of 

 interest, the coral-reefs of the Maldives, 

 Laccadives and Ceylon have an interest 

 of their own in regard to their mode of 

 formation and growth, the fauna by which 

 they are inhabited, and the evidence they 

 afford either of upheaval or of sub- 

 sidence in this part of the Indian Ocean. The managers 

 of the Balfour studentship, with the assistance of dona- 

 tions from the Government Clrant Committee of the 

 Royal Society and the British Association, were therefore 

 well advised in selecting this area as one where a careful 

 and detailed geographical and zoological survey would 

 be likely to yield results of the highest scientific import- 

 ance. So far as can be judged from the small section 

 of the work now before us, Mr. (jardiner, ably seconded 

 by Messrs. Borradaile and Cooper, appears to have 

 carried out his task with great thoroughness and 

 success. A part of the time, it is true, he was incapaci- 

 tated from work by illness, but during his absence the 

 researches were carried on with vigour by Mr. Cooper, 

 who took no less than eighty-eight dredgings in five 

 different atolls. 



J "Tile Fauna and Geography of the Maldive and Laccidive Archi- 

 pelagoes, licing the account of the work carried on and of the collections 

 made by an expedition during the years 18^9 and 1000." Edited by J. S. 

 Oardiner. Vol. i., part i. (Cambridge : University Press, 1901.) 



NO. 1692, VOL. 65] 



Until the appearance of the complete work, which we 

 gather will run to at least two volumes, we cannot, of 

 course, lay before our readers the editor's conclusions 

 with regard to the important problem mentioned at the 

 commencement of this article. Neither can we refer to 

 the general fades of the fauna of these islands. Our 

 notice must accordingly be restricted to the general 

 introduction to the work and the four chapters which 

 (together with a description of certain sections of the 

 fauna) constitute the part before us. 



For reasons connected with the meteorological con- 

 ditions prevailing in the Indian Ocean, it was decided to 

 devote the summer of 1899 to a thorough survey of 

 Minikoi, the most southern atoll of the Laccadives. This 

 island forms the subject of two out of the four chapters 

 already published, and its history is to be continued in 

 those which follow. 



In the introduction, Mr. Gardiner refers to the enormous 

 numbers of the delicate shells of the cephalopod .Spirula 

 met with on the northern end of one island. On inquiry 

 from the natives he found that they were quite familiar 

 with the complete molhisc, which appeared in numbers 

 during the winter of 1897. Strangely enough, however, 

 the creature seems to be extremely local, since it is quite 

 unknown to any of the other islanders. 



In the chapter on its coral islands, the author remarks 

 that the Indian Ocean gives little clue from its topography 

 to the character of the foundations of the various groups ; 

 and in this respect is unlike the Pacific, where the groups 

 run more or less nearly parallel to one another and to 



Fig. I. — Cocnobita ctypeattts using a broken 



the adjacent continent. In one respect the two oceans 

 present a striking similarity, namely, in the absence or 

 paucity of coral-islands on their eastern ' sides. In the 

 Pacific this absence is complete ; in the Indian Ocean it 

 is broken only by Cocos-Keehng and Christmas Islands. 

 In the Indian Ocean this scarcity of islands on the 

 eastern border is, so far as it goes, in favour of the view 

 that the numerous islands on the western side formed 

 part of a land-connection. This belt between Mada- 

 gascar and India is cut, says the author, to a depth of 

 more than 2000 fathoms in three places, to wit, between the 

 Maldives and Chagos, between the latter and Saya de 

 Malha Bank, and again between Farquhar Atoll and 

 Madagascar. " These channels divide the coral-reef 

 areas into four sections, which may be respectively 

 termed the Malagasy, Seychelles, Chagos and Maldive." 

 These four sections are then discussed in detail. 



Chapters iii. and iv. are devoted to part of the descrip- 



1 The author writes '* western,*' but he obviously means '* eastern,'* 



