there is very little soil except that known as " red land," which 

 occurs in the bottom of sink-holes and locally in swales, and the 

 " white land," formed from the crumbled rock either disintegrated 

 in place or accumulated as sand dunes. These two formations 

 represent practically all the tillable land of the islands. Owing 

 to the porous nature of the material there are no known perma- 

 nent fresh-water streams although there are a number of salt- 

 water creeks of considerable size. Occasionally there are fresh- 

 water ponds and marshes, mostly of small size. These very 

 local ponds and marshes furnish many of the botanical novelties. 

 Salt-water ponds which rise and fall with the tide are abundant 

 and sometimes of large size. 



The Bahamas are very recent geologically, the Bahamian up- 

 lift being placed not earlier than the late Tertiary, so that they 

 offer excellent opportunities for the study of plant migration and 

 evolution. The flora is of southern derivation, a large number 

 of the known indigenous species being common to the near-by 

 and older islands of Cuba and Hayti, while many other species 

 are closely related to plants from these islands. The chief agents 

 in the introduction and distribution of the plant population are 

 migratory birds, supplemented b}- winds and ocean currents. 

 Notwithstanding the geologically short period that the Bahamas 

 have been above the sea, they have witnessed the evolution of 

 numerous species, there being many endemic species known and 

 many more which will be made known as the result of the recent 

 explorations. Many of these, it is believed, will prove to be 

 examples of rapid evolution (mutation). 



Dr. Britton's observations were followed by remarks on " Col- 

 lecting Algae in the Bahamas," by Dr. Marshall A. I lowc. The 

 shores of the islands were said to offer a considerable variety of 

 jjjiysical conditions and to have a marine flora which is on the 

 whole varied and rich, though apparcnlK' less so than that of 

 the Florida Keys. The shore-lines are usually rocky, but there 

 are often stretches of white sand which are nearly destitute of 

 algae. The tide rises and falls ordinarih- from one to four feet, 

 but the withering effect of the sunshine is such that few sjiecies 

 are found in the strictly littoral zone except under shelving rocks 



