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1898 ] CURRENT LITERATURE 293 
and later turning downwards. The others grow from the branches of the 
tree perpendicularly downwards, branching at the surface of the water where 
the tips die and decay.. The structure of these aerial roots is fully described. 
5. The vegetation of the salt clay plains. These stretches surround the 
lagoons and salt ponds and upon them is an overflow of some of the forms 
described above. In drier localities live some herbaceous forms and some of 
those growing erect on the beaches are here recumbent. 
Under the forest and thicket vegetation each island is discussed sepa- 
rately. The Hurricane island, which forms the western boundary of the 
harbor of St. Thomas, is sparsely inhabited and mostly covered with a xero- 
phytic vegetation, whose density is increased by thorn growths and lianas. 
The trees are generally smooth leaved, the shrubs hairy leaved, and the most 
important succulents are the agaves, bromelias, and some opuntias. 
n the interior of the island of St. Thomas grow many croton bushes, as 
well as forests of larger trees, a long list of which is given. Epiphytic 
orchids, arums and ferns also abound, Cuscuia Americana being especially 
widespread. St. John is very fertile, though little cultivated on account of 
the indolence of the natives. 
Lately some promising experiments with the cultivation of coffee and 
cocoa have been undertaken. The croton underbrush has been pretty well 
crowded out of this island, and there are great grassy stretches near the 
deeper forests. St. Croix is the most important of the Danish Antilles, and 
is the chief seat of the Danish cane-sugar industry. In the uncultivated por- 
tions the vegetation is similar to that of the other islands. Upon the fallow 
fields the weeds are always woody. The gray crotons cover most of the east- 
ern half of the island, and are more xerophytic and smaller than elsewhere. 
Only a few trees are found, and lianas are scarce, but the succulents richly 
supply their place. The chief characteristic of the vegetation is its xerophy- 
_ tic adaptation. With the exception of the legumes, the leaves are entire, 
stiffy haired, usually ovate and short stemmed. Thorns of every sort abound. 
In the valleys we find the luxuriant vegetation of the tropics, oranges, figs, 
etc. Upon the trees was seen the Tillandsia, and in damp places Psilotum 
and Pilea macrophylla. 
In the last division of the second part the author treats of the anatomy of 
the xerophytic foliage leaves>-having investigated three groups: (1) the 
decidedly hairy leaves; (2) the slightly hairy and smooth leaves, (3) two 
types of leguminous leaves. He thinks the structure of the smooth leaves 
not anatomically different from that of the hairy leaves, but the outer epider- 
mal walls are very much thicker. This is also true of the leguminous leaves. 
The abundant glandular hairs are depressed on the smooth leaves, and stand 
among the other hairs on the hairy leaves. They closely resemble the hyda- 
thodes described by Haberlandt. The leaf anatomy of Evolvulus nummu- 
faris and of Loranthus emarginatus is fully described.—S. M. COULTER. 
