256 PLANTS, SEEDS, AND CURRENTS 



rising from the ocean's depths, which along a length of several 

 hundred miles exhibit a line of peaks that in all cases end abruptly 

 at or near the ocean's surface. The implication is that atolls origin- 

 ally crowned the summits of these submerged peaks in Bahamian 

 seas, atolls long since overwhelmed by the shifting sand-dune, the 

 work of which is presented in the seolian sandstone of our own day. 

 But, as in the line of atolls formed by the Laccadive and Maldive 

 archipelagos, there is a " continental " end, where the Bahamian 

 archipelago abuts on the adjacent continent, and an "oceanic" end, 

 where it projects into the ocean's depths. 



The standpoint adopted with regard to the problems offered by the 

 Bahamas would, I think, largely depend on whether the investigator 

 was familiar with the western or " continental " portion or with the 

 eastern or " oceanic " portion. The points of view might differ 

 materially. Politically as well as geographically the western area 

 is by far the most important ; and from the time of Catesby, nearly 

 200 years ago, to that of A. Agassiz in our own day, the experience 

 of the west has largely coloured the views of the majority of investi- 

 gators. Agassiz, it is true, made a general examination of the 

 archipelago; but his acquaintance with the west principally deter- 

 mined his views. On the other hand, the present writer's experience 

 was limited to a three months' sojourn in the Turks Islands at the 

 extreme eastern end of the archipelago, during which period he made 

 a fairly detailed examination of all the islands of the little group. 

 He may thus claim to be an exponent of the " oceanic " standpoint. 



Much mystery surrounds the history of the Bahamas. The view 

 that there are atolls buried beneath the seolian deposits does not 

 involve any change of level, since the sand-dune could have effected 

 all that we see at present without the assistance of a movement of 

 upheaval. When, as with the Turks Islands Bank, the original 

 bank was long and narrow, the atoll form of reef would be replaced 

 by a reef of similar shape. But on a broad platform, like that pre- 

 sented by the neighbouring Caicos Bank, a typical atoll might have 

 been formed, of which we may discern the remains now in the broken 

 margin of islands and in the extensive flats in the interior of the 

 bank that are now covered by only a few feet of water. However 

 this may be, all that we see at present could have been produced at 

 the existing sea-level. Different periods of upheaval and subsidence 

 of the Bahamian area have been postulated by geologists and 

 zoologists; but, without entering into matters that are mainly 

 inferential, I will at once proceed to refer to the account of these 

 islands given by A. Agassiz in his Reconnaissance of the Bahamas 

 (Bull. Mus. Comp. Zool. Harvard, 1894), a work from the hand of one 

 of the foremost investigators of our time. 



A. Agassiz on the Formation of the Bahamas. — After remark- 

 ing that the islands of the Bahamas are from end to end all of seolian 

 origin, he thus proceeds — 



" They were formed at a time when the banks up to the ten-fathom 

 line must have been one huge irregularly shaped mass of low land, 

 the coral sand beaehes of which supplied the material that must 

 have built up the successive ranges of low hills which we still find in 



