DEPARTMENT OF MARINE BIOLOGY. 



H3 



All of the transplanted colonies still alive were fastened to the shelf of 

 the moat wall with hydraulic cement, to prevent their washing away, and 

 growth observations are now being made on all of them. 



Notes on the general vital conditions of the moat are given imder "Annual 

 surveys of the Fort Jefferson moat." 



The transplanting experiments to the moat and the records of corals grow- 

 ing naturally in it give qualitative, not quantitative, results, but they show 

 that certain corals can stand considerable ranges in the temperature of the 

 water and variation in the degree of salinity. 



Rearing Corals from the Young. 



The live-car in which the young of Favia fragum attached to the bottom 

 of a glass dish were placed in July, 1908, was unfortunately broken from 

 its mooring by a storm during the winter and that experiment was termi- 

 nated. The experiments made in May, 1908, clearly showed the feasibility 

 of having the planulse of corals attach themselves in the laboratory, and 

 planting them in desirable localities. It was decided to use as collectors cir- 

 cular tiles, 8 inches in diameter and i inch thick, perforated in the center by 

 a square hole, which fits over the head of an iron stake. An iron stake can 

 be driven into the reef or any other selected place, a tile fitted over its head 

 and made fast by a key and wedges. After a number of planulse have been 

 extruded from a colony, they are pipetted off and placed in a vessel contain- 

 ing a tile on its bottom. Although a good many planulse settled on the tiles, 

 many had a persistent tendency to seek the bottom of the vessels outside the 

 periphery of the tile or through its central perforation. In order to pre- 

 serve these specimens the glass vessels were broken and the pieces bearing 

 the young corals were attached with hydraulic cement to tiles. 



Nine tiles, having on them the young of Agaricia and 2 species of Pontes, 

 were planted on a reef off Loggerhead Light. The parent colonies were pre- 

 served for comparison with their offspring. After I left the Tortugas, Dr. 

 Mayer cemented 3 additional tiles bearing the young of the same species to 

 the shelf of the Fort Jefferson moat, near the western entrance. Therefore, 

 12 tiles bearing attached larvae were planted. 



Duration of the Free-swimming Larval Stage of Corals. 



In the last Year Book of the Carnegie Institution of Washington (pp. 135, 

 136) I published that the free-swimming larval stage of Favia fragiini was. 



10 — YB 



