288 



BOTANICAL GAZETTE 



[OCTOBER 



several places, however, the dunes have either not formed there, 

 or have passed back, leaving a golden brown slab of hard 

 material. On the beach pieces of iron ore were found, washed 

 from an undetermined source. Back in the dune region are 

 tracts of lancl almost totally destitute of vegetation {^fig. 2). 

 These desert spaces are rain-washed in times of storm, and hold 

 water for some little time, the water washing into the depression 



-*r 





■ H^ 



-^ 



t i^-H 





J%» 



-T ^ 



> _^n ^ — 



■>v 





■*?.* 



■^ V 



^s;- 



^ 





p.' 



.^r■ 



_ Si 



.J5^ 



-m. 



*5^ 



■--^-' 



Fig. 2. — Bare space between dune series; second series immediately beyond, on 

 crest of which a thicket is forming ; forest beyond. 



from a higher region, and then evaporating, covering the ground 

 with a deposit of sand and clay, which becomes baked in the 

 hot sun. The ground is so unfavorable for the existence of 

 plants, that very little vegetation Is found here. In the swamps 

 and meadows a layer of humus covers the sand to a greater or 

 less depth, according to the character of the vegetation, the 

 exposure, and the length of time of deposition. 



2, Soil water. — Water level is very near the surface, in 

 most places only a slight depression being needed for the devel- 

 opment of a swamp. The water furnished by pumps in the vil- 



I 

 I 



y 





!;■ 



? 



I- 



