380 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1917. 



The rock which underlies the Everglades and appears on the sur- 

 face on the keys and pinelands of southern Florida is known to 

 geologists as Miami oolite. Its outcrop at Long Key, the great rock 

 barrier adjacent to the northern boundary of Royal Palm State 

 Park, as well as at other points, was noticed by Army officers at the 

 time of the Seminole War. Specimens from the vicinity of Paradise 

 Key in the collection of the United States National Museum contain 

 fossil bivalve shells; others (pi. 2) contain vermicellilike casts of 

 annelids, and others hollow tubes, apparently formed by crustaceans 

 in soft mud, now lined with crystalline calcite. This oolitic lime- 

 stone, as Dr. T. Wayland Vaughan has pointed out, is not of animal 

 origin, but a chemical precipitation of calcium carbonate in the form 

 of minute granules ; it plays a much greater part in the construction 

 of Florida reefs than corals. 1 It was originally deposited in a shal- 

 low sea, just as similar sediment is now being precipitated in the 

 Bahama Islands. Dr. Karl F. Kellerman, of the Bureau of Plant In- 

 dustry, made a careful bacteriological study of samples of water and 

 calcareous mud from the ocean bottom near the Bahamas and the 

 Florida keys. He found the water laden with calcium bicarbonate 

 and filled with certain bacteria which liberated ammonia. The action 

 of the ammonia on the calcium bicarbonate caused a precipitation 

 of calcium carbonate, which assumed the form of oolite. The bac- 

 terial origin of calcium carbonate had previously been suggested by 

 the late George H. Drew of the Carnegie Institution, who succeeded 

 in isolating an organism which he named Bacterium calcis. Doctor 

 Kellerman repeated his experiments and confirmed his observations, 

 referring the above-mentioned organism to the genus Pseudomonas, 

 under the name Pseudoirwruis calcis. 2 



WATER PLANTS. 



The deep slough to the eastward of Paradise Key (pi. 3), which 

 has already been mentioned as its chief protection from destructive 

 agencies, is filled with a dense growth of water plants : yellow water 

 lilies, or spatter-docks (pi. 4) ; Sagittarias, with broad, three- petaled 

 white flowers (fig. 1) ; pickerel weed, with spikes of blue flowers 

 (fig. 2) ; water arums (fig. 3) related to our jack-in- the-pulpit and 

 with roots equally filled with needle-like raphides which burn the 

 mouth like fire; white-flowered floating hearts (fig. 4) resembling 

 miniature pond lilies, but not botanically related to them; and tall 

 water weeds (Oxy polls filiformis) belonging to the same family as 

 the celery, but with hollow, quill-like tubes for leaves. 



1 See Vaughan, T. Wayland, Sketch of the geologic history of the Florida coral reef 

 tract and comparison with other coral reef areas. In Journ. Wash. Acad. Sci. 4 : 26. 

 1914. See also " Corals and formation of coral reefs " by the same author, in the present 

 volume. 



2 See Kellerman, Karl F., and Smith, N. R., Bacterial precipitation of calcium car- 

 bonate. Journ. Wash. Acad. Sci. 4 : 400. 1914. 



