458 



SCIENCE 



[N. S. Vol. XLI. No. 1056 



dence, so that the earlier-formed reefs, which 

 began to grow when the subsidence was slowly 

 initiated, were drowned when it was later 

 accelerated; and new reefs, thereupon begun 

 on the shore line of that time would after a 

 second period of slow subsidence stand near 

 the present shore line, though the shore line is 

 strongly embayed because the total subsidence 

 has been large. The absence of reefs around 

 the island of Ambrym is due to its abundant 

 eruptions in recent time, the latest one being 

 in December, 1913; scattered corals were seen 

 growing on one of its sea-clifled lava-streams, 

 thus illustrating the initial stage of a fring- 

 ing reef. 



The Great Barrier reef of Australia, the 

 largest reef in the world, with a length of 

 some 1,200 miles and a lagoon from 15 to 70 or 

 more miles wide, has grown upward during 

 the recent subsidence by which the Queensland 

 coast has, after a long period of still-stand, 

 been elaborately embayed, as was pointed out 

 by Andrews in 1902. A very recent uplift of 

 ten feet has occurred, as was long ago noted 

 by Jukes. There is reason for believing that a 

 hroadened reef-plain, with extensive land-fed 

 deltas along the continental margin, had been 

 formed before the recent subsidence took place ; 

 and it is this broadened reef, now submerged, 

 that is thought to form the " platform " on 

 which the Great Barrier reef has grown up. 

 Guppy's suggestion that the platform or " sub- 

 marine ledge " is due to marine abrasion before 

 coral reefs were established here and that no 

 subsidence has taken place can not be accepted. 

 It is highly probable that the well-attested 

 recent subsidence was due to a gentle flexure, 

 Ijy which the off-shore sea-bottom was bent 

 down; and if so, the coastal submergence will 

 give much too small a measure of the thickness 

 of the distant barrier reef. In this respect the 

 Great Barrier reef along the shore of a conti- 

 nent differs significantly from smaller barrier 

 reefs around oceanic islands, in which the 

 subsidence of the island and its reef are essen- 

 tially uniform. 



A few hours on shore at Earetonga, the 

 southernmost member of the Cook group, 

 sufficed to show that extensive embayments 



formerly entering its elaborately carved mass 

 are now occupied by delta plains and perhaps 

 in part by slightly elevated reef- and lagoon- 

 limestone. 



Five islands of the Society group exhibit 

 signs of recent subsidence in their intricately 

 embayed shore lines, as has lately been an- 

 nounced by Marshall. A sixth, the cliff- 

 rimmed island of Tahiti, the largest and 

 youngest of the group, has suffered moderate 

 subsidence after its cliffs were cut, but the re- 

 sulting bays are now nearly all filled with 

 delta plains which often advance into the nar- 

 row lagoon; hence a pause or still-stand has 

 followed the latest subsidence. All the barrier 

 reefs of this group appear to have been formed 

 during the recent subsidence that embayed 

 their central islands. 



W. M. Davis 



Haevaed University 



SCIENTIFIC NOTES AND NEWS 

 Dr. Eichard P. Strong, professor of trop- 

 ical diseases at the Harvard Medical School, 

 has been appointed leader of the American Eed 

 Cross Sanitary Commission, which will assem- 

 ble in Salonica about the middle of next month 

 and proceed to the districts of Servia and 

 Austro-ITungary which are stricken with epi- 

 demics of typhus, cholera and other contagious 

 diseases. The commission will be supported 

 by the Eed Cross and the Eockef eller Founda- 

 tion. Dr. Strong has already sailed for Greece, 

 and the rest of the expedition will sail by the 

 end of this month. It includes Dr. Thomas 

 W. Jackson, of Philadelphia; Dr. Hans 

 Zinsser, professor of bacteriology, Columbia 

 University; Dr. Andrew W. Sellards, Dr. 

 George C. Shattuck and Dr. Francis B. Grin- 

 nell, of the Harvard Medical School. Dr. 

 Nicolle, the French expert on typhus, has been 

 invited to cooperate with the commission. Mr. 

 Charles S. Eby, of Washington, lately con- 

 nected with the United States Immigration 

 service, is disbursing officer and secretary for 

 the commission. 



The Eoekefeller Foundation has made com- 

 prehensive plans for improving medical and 

 hospital conditions in China. These are based 



