1917] HARRIS & LAWRENCE—TISSUE FLUIDS 287 
Pen. The desert is confined to the limestone areas which have an 
extremely rough surface, with layers or shallow pockets of soil 
which are not capable of retaining moisture or of deriving it by 
capillarity, and to the finely ground substratum of the coastal 
flats. The proximity of the sea and other factors maintain a high 
relative humidity. Atmometer readings by SHREVE indicate that . 
the evaporation rates here and at Hope Gardens, which is some 6 
miles inland and behind a low ridge of hills, are not very different. 
All of our collections were made in the immediate vicinity of Port 
Henderson, a point easily accessible from Spanish Town, where it 
was possible to carry out the laboratory phases of the work, and 
which afforded access to both the rocky limestone hills and the 
coastal flats. Because of military restrictions, made with great 
courtesy, we were unable to visit all parts of the region. Probably 
distribution of the collections over a wider area would have modified 
but little the cache here drawn, anne it _—— have in- 
creased the number of species upon which de are based. 
The area considered comprises open beach, a mangrove swamp, 
a highly saline tract of mud flats practically free of vegetation, 
somewhat higher-lying flats of finely ground detrital material, and 
rocky limestone hills, the soil = which i is relatively ane om 
retaining water. = 
The determinations hick we we made on the plants of the om 
each and on those of the a grove swamp resel ae for a lis u : . : : 
pep eEse ties of strand and mangrove swamp species, = 
to be published laer " data a. other habitats (many of - rhich 
have already been collected) are ready. The vegetation of ie ee 
, rpalaigcd — aud flats is practically limited to the two well aS 
, of = . 
eet ie former i is much the more ‘common, and the two ‘man- Se : 
: Avicennia nitida and —e racemosa, which occur 
