164 CARNEGIE INSTITUTION OF WASHINGTON. 



Rebecca Shoal Lighthouse is out in the ocean, the nearest land being 

 East Key, Tortugas, distant about 12 nautical miles; but the nearest 

 region upon which any considerable number of mosquitoes can breed 

 is Marquesas Atoll, 24 miles to the eastward. Professor Ball found 

 that breezes from the north and east brought mosquitoes to the light- 

 house, and on July 11 a swarm came with the strong southerly wind 

 from Cuba, 95 miles away. This same swarm appeared also at Tor- 

 tugas and became a pest for a few hours, causing us to retreat from the 

 beach and retire at night under our mosquito bars, an unusual con- 

 dition in this region, where mosquitoes are uncommon. Professor 

 Ball's study makes it appear that strong winds can carry mosquitoes, 

 flies, and other insects with the drift of air for 95 miles, and although it is 

 not denied that mosquitoes may at times fly for considerable distances 

 against light breezes, experience at Tortugas and Rebecca Shoal would 

 seem to warrant the conclusion that a strong breeze is far more efficient 

 in carrying them for long distances with the wind than is a light breeze 

 in enabhng them to fly against the wind. 



Dr. Paul Bartsch visited the Tortugas, hoping to find many adult 

 specimens of the second generation of Cerion snails born on the Tor- 

 tugas, but these animals grow so slowly and he found so few adults 

 that no conclusions can with safety be drawn. These cerions were 

 brought in 1912 and at other times from Andros Island, Porto Rico, 

 Curasao, and the Bahamas to Tortugas and other Florida keys and 

 have flourished remarkably well in some places, the first generation 

 being generally larger than their Bahama and West Indian ancestors. 



Professor Lewis R. Gary is extending to the Pacific his determina- 

 tion of the share alcyonarian corals take in building up reef limestones, 

 and also studying the reaction to temperatm-e, growth-rate, ecology, 

 and metabolism of these forms and has demonstrated that they con- 

 tribute more limestone to the Florida-Bahama reefs than do the madre- 

 porarian corals. It will be necessary for him to return to Samoa in 

 order to ascertain the gi'owth-rate of these forms and to drill through 

 the reef and obtain a core to determine the relative amounts of madre- 

 porarian and alcyonarian materials constituting the limestone. Other 

 researches undertaken by Professor Gary are referred to in his report 

 published herewith. 



Dr. Hubert Lyman Glark collected echinoderms at Tortugas and 

 found 75 species on the reefs and in the channels of the group. The 

 region thus appears to be as rich in number of species as is any other 

 part of the West Indies, although some forms which are abundant else- 

 where are rare at Tortugas. 



Dr. Shinkishi Hatai found that the brain-weight in the gray snapper, 

 Neomomis griseus, a common predatory fish of the Florida reefs, bears 

 a hnear ratio to the body-weight. He also carried out a study of the 

 changes occurring in Cassiopea during starvation and found that the 



