DEPARTMENT OF MARINE BIOLOGY. 183 



Besides his (loterniinutions of salinity, Mr. Dole also investigated the 

 amount of dissolved oxygen in the Tortugas waters. Though he does not 

 report his results in detail, he says that the sea-water is practically saturated, 

 a state indicating that there is plenty to oxidize decomposing matter with- 

 out danger of anaerobic conditions. 



As the program for studying the Florida shoal-water corals is now ap- 

 proaching its conclusion, a statement of additional desiderata will be made, 

 as follows: (1) to continue the growth observations for at least two more 

 seasons; (2) to complete the inspection of the Tortugas area for the location 

 of the reefs, coral patches, etc. ; (3) to dredge from shoal water to a depth of 

 50 fathoms, take temperature readings, and collect bottom samples; (4) to 

 conduct experiments on the upper and lower temperature limits at which 

 the different species of shoal-water corals will take food; (5) to conduct 

 experiments on the minimum and maximum salinity (amount of dilution 

 and concentration of sea-water) corals will endure; (6) to conduct additional 

 experiments on the exclusion of light from shoal-water corals; and (7) to 

 ascertain the length of the free-swimming larval stage of several other 

 species. Although this list is rather long, the fulfillment of the requirements 

 of each item is simple. 



Investigations of the Geology and Geologic Processes of the Reef Tracts 

 and Adjacent Areas in the Bahamas and Florida, by T. W. Vaughan. 



During the office season of 1912-13 much laboratory work was done on 

 the bottom specimens and lithologic samples obtained in Florida and the 

 Bahamas during the field season of 1912. I devoted considerable time to 

 studying the material and was enabled to announce that — 



"The empirical facts in the process of the formation of the Floridian and 

 Bahaman oolites are demonstrated. They are as follows: (1) Denitrifying 

 bacteria are very active in the shoal waters of both regions and are precipi- 

 tating enormous quantities of calcium carbonate which is largely aragonite ; 

 (2) this chemically precipitated calcium carbonate may form spherulites 

 which by accretion may become oolite grains of the usual size, or it may 

 accumulate around a variety of nuclei to build such grains."* 



The study of this material is still in progress, and the report on it is not 

 yet complete. In order that it might receive the most thorough treatment 

 possible the assistance of a number of specialists was obtained. Dr. F. E. 

 Wright, of the Geophysical Laboratory, examined some of the bottom 

 samples; Dr. J. A. Cushman, of the U. S. Geological Survey, has furnished 

 lists of the foraminifera; the chemical laboratory of the U. S. Geological 

 Survey has had a series of chemical analyses of bottom samples and speci- 

 mens of oolite made by one of its staff, Mr. W. C. Wheeler; physical analyses 

 of a set of samples are being made by Mr. E. W. Shaw, of the U. S. Geolog- 

 ical Survey, in association with the Bureau of Soils of the Department of 

 Agriculture; and Dr. Paul Bartsch, of the U. S. National Museum, will 

 report on the fossil moUusca of the oolites. Dr. Bartsch is also preparing 

 a special report on boring organisms that cause the disintegration of coral 

 skeletons. 



In addition to that regarding the formation of oolite, a few other general 

 statements as to the shoal- water calcareous muds of the Florida key region and 

 of the Bahamas may be made. Except in the region of Biscayne Bay, the 

 chemical analyses show a high percentage of calcium carbonate, over 90 per 

 cent. There is not only no terrigenous material in the muds obtained in the 



*Jour. Wash. Acad. Sci., vol. 3, No. 10, p. 303, 1913. 



