456 



APPENDIX 



near by, the lake's level rose eleven inches. On account of the large 

 amount of sediment that must be carried into the basin by the 

 numerous small streams and rivulets that empty into it, the lake is 

 evidently gradually filling up. Most of these materials are deposited 

 in the basin, and I should fancy that in a few centuries the lake will 

 have disappeared. This result will be brought about not merely 

 through the silting process in the basin, but through the deepening 

 of the channel of the effluent by its own erosion. 



During three days in the middle of February, when the tempera- 

 ture of the air in the shade at the lake-side ranged between 65*5° 

 and 73*0° F., that of the water of the lake's surface ranged from 

 71*8° to 73-7° F., and that of the effluent 71 5° to 72'8° F. 



Note 9 (pp. 13, 87, 92). 



Guilandina bonduc and other species. 



Guilandina bonduc, though fairly well distributed, is not nearly so 

 common in the West Indies as G. bonducella. Though both are 

 littoral species, G. bonduc seems to be the species that is most at 

 home inland. But the questions raised by these two plants, that 

 often travel around the tropics of the world together, are much 

 more complex in the New World than in most other regions. Yet 

 even in the Pacific islands, as I have shown in my work on Plant 

 Dispersal, they give rise to several difficulties; but the tendency to 

 differentiation that they there display is much more marked in the 

 American continent, and there is ground for the belief that the two 

 types will admit of being broken up into several smaller specific or 

 subspecific groups. Urban in his Symbolce Antillance (II., 270-6), 

 though he does not separate them from the Csesalpinias, describes 

 eight or nine peculiar West Indian species of the Guilandina type, 

 usually with yellow or orange-coloured seeds, and mostly from Cuba. 

 But island groups like the Bahamas, and even the Caymans, may 

 possess their own peculiar forms, and Millspaugh has described a 

 new shore species from the last-named locality that stands nearest 

 to G. bonducella (Plantar Utowanai). 



My inference in the Pacific that seed-buoyancy in Guilandina 

 goes with station rather than with species, plants of the beach 

 having buoyant seeds and those from inland seeds that sink, would 

 not seem to be of general application in the West Indies. Thus on 

 the beaches of St. Croix I found Guilandina bonduc associated with 

 G. bonducella, but only the last had buoyant seeds. Indeed, my 

 data seem to indicate that in the West Indies seed-buoyancy in 

 Guilandina goes with species rather than with station. When in 

 Grenada I tested the buoyancy of the seeds of G. melanosperma, a 

 variety of G. bonduc with black seeds, from Antigua; but they all 

 sank in sea- water. The lack of buoyancy of the seeds of this species 

 in the West Indies may be predicated from their rarity in beach- 

 drift. An indication in the same direction for the genus is afforded 

 by the fact that in the case of an inland species, apparently un- 

 described, that I found in the woods on the lower slopes of Mount 



