DEPARTMENT OF MARINE BIOLOGY.^ 



Alfred G. Mayor, Director. 



The unfortunate death of Dr. Mayor occurred before he had accumulated 

 material for his annual report. The investigators, however, who have been 

 engaged in researches during the past year in collaboration with the Depart- 

 ment of Marine Biology had been asked by him to prepare reports for this 

 purpose; these reports are printed herewith. 



The work of reconstruction of the Tortugas Laboratory, which was begun 

 in 1921, as reported by the Director last year, was completed during the past 

 season under the direction of the chief engineer, Mr. John W. Mills. The 

 interior of the new laboratory building was finished and an iron-piered wharf 

 extension was built. The moat surrounding Fort Jefferson having been 

 wholly abandoned by the U. S. Navy, the breach in the moat wall, caused by 

 the hurricane of 1919, was repaired last year and Cassiopea has reappeared. 

 Dr. Mayor, therefore, had the satisfaction of realizing that the Tortugas 

 Laboratory was in an excellent state of repair and that its facilities for effective 

 work had never been better. 



Attention may be directed to the observation in the report of Dr. Bartsch 

 with regard to the rapid reestablishment of adequate vegetation and animal 

 life in the waters of Florida Bay. 



During the year the Anton Dohrn was equipped especially for work in the 

 Gulf Stream, with cables, current meters, and sounding machines, in expecta- 

 tion that extensive investigations in this region would be undertaken sub- 

 sequently. 



Owing primarily to the Director's continued ill health, only a short season 

 was planned at Tortugas, but a number of investigators whose researches 

 required extension or completion accepted invitations to visit Tortugas or to 

 continue work elsewhere. 



The following studied under the auspices of the Department during the 

 year : 



Dr. Paul Bartsch, Florida Keys (Miami to Tortugas), May 7 to May 23. Breeding experi- 

 ments with cerions. 



Professor Ulric Dahlgren. Study of luminous Crustaceae and fishes in vicinity of Miami, 

 Florida. 



Professor John H. Gerould. Studies on the Pieridaj. 



Professor E. Newton Harvey. Production of light by animals. 



Professor C. B. Lipman, assisted by Mr. R. L. Starkey, Tortugas, June 6 to June 23. The 

 precipitation of calcium carbonate by marine bacteria. 



Professor William H. Longley, Tortugas, June 6 to July 24. The habits of Tortugas fishes. 



Dr. Alfred G. Mayor, Tortugas, May 5 to June 24. 



Dr. Sergius Morgulis, Tortugas, June 6 to July 24. Studies of the blood of the Tortugas 

 crawfish, Panulirus argus, and of a nurse shark. 



Captain Frank A. Potts, Tortugas, June 27 to July 24. 



Professor Asa A. Schaeffer, Tortugas, June 6 to July 3. Marine amebae. 



Professor WilHam A. Setchell. Reconnaisance of the vegetation of Tahiti, with special 

 reference to that of the reefs. May 16 to July 19. 



Dr. T. Wayland Vaughan. Studies of fossils from Walu Bay and of corals and bottom 

 samples from Samoa and from the Bahamas and Florida. 



'Situated at Tortugas, Florida. 



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