52 PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



office facilities in Washington, for the study of collections and the prepara- 

 tion of reports, should be furnished by the U. S. Geological Survey. The 

 held work has been completed as originally planned, but all the contem- 

 plated reports have not yet been submitted for publication. 



As I had been continuously engaged on studies of the geology and 

 geologic history of the Coastal Plain of the United States since about 1889, 

 as the motive for my investigations on corals was to obtain information for 

 use in interpreting geologic history, and as I was in charge of the geologic 

 investigations of the Coastal Plain for the U. S. Geological Survey at the 

 time I began work in association with the Marine Biological Laboratory, 

 it is natural that the opportunity to study the great variety of geologic 

 processes and other geologic phenomena, so well exemplified in southern 

 Florida and the Bahamas, would not be neglected. Furthermore, as I had 

 been engaged in studying the stratigraphy, paleontology, and geologic history 

 of the perimeters of the Gulf of Mexico and the Caribbean Sea ever since I 

 began geologic work, provisions for an extension of my experiences in the 

 region came from a number of sources. In 1901 I was one of three geolo- 

 gists detailed by the Director of the U. S. Geological Survey to the Military 

 Governor of Cuba for the purpose of making a geologic reconnaissance of 

 that island; minor grants from the Carnegie Institution of Washington 

 made possible investigations in the Lesser Antilles; and the Isthmian Canal 

 Commission and the U. S. Geological Survey supported field work in the 

 Canal Zone. Having received assistance from so many organizations in 

 a complex of interlocking problems, it is well-nigh impossible to be specific 

 in acknowledging the credit due each. 



The investigations have been according to a plan which will here be 

 briefly outlined, first considering those on the variation and ecology of corals, 

 the outline for which was given in my paper on the Madreporaria of the 

 Hawaiian Islands and Laysan, as follows: 



"Variation in the Madreporaria 1 should be studied in three ways: (1) In nature 

 without experiment; (2) in nature by experiment; (3) under artificial conditions 



in aquaria. 



"1. In nature without experiment. — Coral fields, according to this method, 

 should be ecologically surveyed. The study of specimens of the same species 

 obtained under the same physical conditions would give information on gametic 

 variation, while the comparative study of specimens belonging to the same species, 

 obtained under different physical conditions, would throw light on the influence 

 exerted by the environment. Numerous fragmentary studies of this kind have 

 been made, but none has been thoroughly done. As much information obtained 

 in this way, as is possible, is given in the present memoir. 



"2. In nature by experiment. — By planting attached young under the same 

 physical conditions gametic variation could be observed. By transplanting speci- 

 mens from one area to another, or by planting the young of a given colony under 

 different physical conditions, the effect of environment could be studied. 



'U. S. Nat. Mus. Bull. 59, pp. 6-7, 1907. 



