January 30, 1903.] 



SCIENCE. 



191 



Not one of the pelagic animals which 

 abound at the Tortugas has been found living 

 permanently north of Cape Cod, Massachu- 

 setts, although a large number of Tortugas 

 species are annually drifted upon the south- 

 ern coast of New England by the prevailing 

 southerly winds of the summer months. The 

 pelagic fauna of the Tortugas is, on the other 

 hand, closely related to that of the Fiji Is- 

 lands, both in the nature of the specimens 

 themselves and in the relative abundance of 

 characteristic forms, although slight specific 

 distinctions can usually be jierceived which 

 separate the Tortugas from the Fijian forms. 



About ten- squa,re miles of shallow reef 

 flats He around the Tortugas Islands and 

 these support a fauna which, for variety and 

 abundance, appears to be unsurpassed by that 

 of any other situation in the Atlantic. 



The Madreporaria, however, are poorly rep- 

 resented in the Tortugas, but previous to 

 1878 the coral reef was remarkable for both 

 the number and variety of species represented. 

 In October of that year a dark-colored water, 

 coming apparently from the mainland of 

 Florida, drifted out over the Tortugas reefs, 

 killing great numbers of marine animals. 

 Practically all of the stocks of Madrepora 

 murciata were killed at this time, and this 

 coral is still extremely rare at the Tortugas, 

 only a few stocks being found at depths of 

 two fathoms or more. The genera Pontes, 

 Orhicella and Meandrina, on the other hand, 

 appear to have survived in considerable num- 

 bers, for many heads of these corals are now 

 seen, all being far too large to have been 

 formed since 1878. 



As a result of one month's collecting in 

 shallow water, it appears that about 265 

 species of marine animals are very abundant 

 in water less than one fathom in depth, while 

 a far greater number of forms are rare, or 

 found in deeper water. 



Several species of gulls nest upon the is- 

 lands during the summer months, about four 

 thousand of them annually visiting Bird Key 

 late in April and remaining to attend their 

 young until the third week in August. These 

 gulls are the noddy {Anonus stolidus), the 

 sooty tern (Sterna fuUginosa), the least tern 



{S. antillarum) . The man-of-war hawk {Fre- 

 (jata aquila), and the Booby {Sula sula) are 

 sununer visitors. Marine turtles, especially 

 the loggerhead {Thalessochelys caretta), were 

 once abundant upon the Tortugas, but are 

 now becoming rare, owing to indiscriminate 

 and constant persecution. A few females 

 still crawl up on the sandy beaches from 

 between the middle of May and the first week 

 in August and dig their nests near the line 

 of the bushes above the reach of the spray. 

 The eggs hatch in about six weeks and the 

 young crawl immediately into the water. 



The surface hauls obtained in the Tortugas 

 appear to be richer than those gathered in 

 the Bahama Islands, and this is what we 

 should exiject from the prevailing winds which 

 constantly drift the surface waters of the 

 Gulf Stream upon the Tortugas, whereas the 

 Bahama Islands lie to the windward of the 

 great current, which, as every one knows, 

 teems with pelagic life drawn into it from all 

 parts of the tropical Atlantic. 



During the summer months the tempera- 

 ture of the air rarely exceeds 95° F. The 

 humidity is very high, however, although 

 the nights are cool, and the gentle breeze 

 drifting almost constantly over the islands 

 renders it possible to retain normal health 

 and energy. 



The accommodations at the Tortugas con- 

 sist in the oflicers' quarters and barracks at 

 Fort Jefi'erson, the now deserted quarantine 

 hospital on Bird Key, and the buildings at- 

 tached to the lighthouse on Loggerhead Key. 

 Ofiicers of the United States government 

 have, upon all occasions, displayed co7nmend- 

 ahle interest in the labors of scientific men 

 at the Tortugas, and have always granted to 

 well-qualified persons the privilege of living 

 within the government buildings. Indeed, 

 our knowledge of the Tortugas fauna is al- 

 most wholly due to the efforts of the govern- 

 ment in forwarding research in this region, 

 and to the private efforts of Alexander Agas- 

 siz, Were a permanent laboratory to be estab- 

 lished upon the Tortugas, however, a com- 

 fortable, well-ventilated wooden building ca- 

 pable of accommodating from six to twelve 

 investigators would be required. This should 



