140 



REPORTS ON INVESTIGATIONS AND PROJECTS. 



V. Calcium Acetate Medium: 



Calcium acetate (Ca(CH 3 - Boiled and filtered before steril- 



COO)2) 5-0 grams. ization to remove precipitate of 



Sodium phosphate (Na 2 - phosphate. 



HPO*, 12H2O) 0.25 gram. 



Potassium nitrate (KN0 3 ). 0.5 gram. 

 Sea-water 1,000.0 c. c. 



VI. Peptone Calcium Acetate Medium: 

 Calcium acetate (Ca(CH 3 - 



C00) 2 ) 5.0 grams. 



Peptone (Witte's) 0.2 gram. 



Potassium nitrate (KNOa). 0.5 gram. 

 Sea-water 1,000.0 c. c. 



Media IV, V, and VI were also made up with the addition of 0.2 gram of 

 magnesium tartrate per 1,000 c. c. 



The fluid media were made in 1,500 c. c. flasks, and 1,000 c. c. of medium 

 was used for each culture. Owing to the high temperature and the lack of 

 ice it was not practicable to employ gelatin media. 



It will be convenient to consider the investigation of the bacteriology of 

 the deep water of the Tongue of the Ocean and that of the chalky mud flats 

 to the west of Andros separately. 



BACTERIAL INVESTIGATIONS IN THE TONGUE OE THE OCEAN. 



Continued bad weather during the whole of our stay at Andros considera- 

 bly added to the difficulties of this work, and on this account it was only 

 found possible to work three stations. The last two were worked under the 

 most disadvantageous conditions, the quick roll of the boat making the fill- 

 ing of the water-bottle with alcohol and the siphoning off of the sample 

 under sterile conditions a matter of the greatest difficulty. 



The first station worked was situated 6 miles due east of Golding Cay, 

 the second 14 miles due east of Golding Cay, and the third station 10 miles 

 ENE.^E. of Golding Cay. 



At the first station, worked on May 8, bottom was sounded at 822 fathoms. 

 The sea was calm at first, with a SSE. swell, but became choppy later. 

 The wind was SSE., force o to 1 at 8 h 30 111 a. m., but freshened considerably 

 later in the day. The sample of the bottom obtained by the snapper-rod 

 consisted of a sticky white ooze, composed of very minute unorganized par- 

 ticles of calcium carbonate, and containing pteropod and globigerina shells. 

 The following temperatures were recorded : 



These samples without previous dilution were plated in peptone agar, 1 

 c. c. of the sample being used for each plate. The agar was cooled to 40 C. 

 before plating. It is very necessary that this temperature should not be ex- 

 ceeded, as many of the marine bacteria are very sensitive to heat. The use 

 of agar at a temperature of 45 ° C. will cause the death of a large proportion 

 of the bacteria, though in the process of plating they can only be exposed 



