150 CARNEGIE INSTITUTION OF WASHINGTON. 



strido. He accordingly devoted his entire time to collecting and study- 

 ing the Eunicidse of Tobago, while Mr. Gay made colored drawings 

 for the extensive work which Professor Treadwell is preparing upon 

 this group of worms. Tobago being in the track of the northern branch 

 of the Great Equatorial drift of the tropical Atlantic, afforded the 

 Director an opportunity to continue his observations upon the 

 siphonophores, and tows were made by Mr. Mills every morning 

 at sunrise for this purpose, good results being achieved, despite the 

 many years the Director has spent in seeking these animals in 

 Atlantic waters. 



We returned to New York on May 8, and it was our intention that 

 Professors Treadwell and Gudger might visit Nassau, Bahamas, accom- 

 panied by Mr. Gay, but enemy submarines appearing off our coast, 

 the sailing schedules of the steamers were so deranged that these plans 

 were abandoned. However, the Director, accompanied by Professor 

 L. R. Gary and Mr. John Mills, again visited Pago Pago, American 

 Samoa, arriving there on July 1 and remaining until August 5, 1918. 



Hon. Josephus Daniels, Secretary of the Navy, kindly permitted us 

 to return to Samoa in order to continue the studies of growth-rate 

 and other factors of coral reefs commenced by us before war was 

 declared in 1 9 1 7 . We were provided with a Davis calyx drilling machine 

 for drilling through the coral reef and bringing out a core, and the 

 United States Shipping Board in San Francisco permitted us to trans- 

 port this to Samoa. 



To Commander John M. Poyer, U. S. N., governor of American 

 Samoa, and to Lieutenant Conmiander L. W. Strum and other naval 

 officers, it is a great pleasure to express our deep sense of gratitude for 

 the kind reception given us in American Samoa. Not only were we 

 the recipients of frequent and significant aid to our studies, but Gov- 

 ernor Poyer placed the U. S, S. Fortune at our disposal to transport 

 the expedition from Pago Pago to Apia, Samoa, thus expediting our 

 return and making it possible for us to stop in Suva, Fiji, where we 

 weighed, measured, photographed, and planted out 140 corals upon 

 the barrier reef off the mouth of Suva Harbor, Viti Levu Island. 



The results already attained show that madreporarian corals in 

 Samoa grow about twice as rapidly as do similar genera off the Atlantic 

 coast of Florida. For example, an Acropora which weighed 2 ounces 

 in 1917 had grown to be 70 ounces at the time of our return 15 months 

 afterwards. Moreover, due to their abundance and rapid growth- 

 rate, the Acropora constitute the most important element in deter- 

 mining the outv/ard growth of the Pacific coral reefs. The large 

 Pontes heads, dangerous to navigation, grow upward at an average 

 rate of about an inch per year. 



Barrels were set out over the edges of reefs swept by currents in 

 order to determine the loss due to sand washed from the shallow reef 



