334 ON THE NATURAL HISTORY OF MADAGASCAR. 
0 
with 500. The large genera of ferns all fall into this category, 
Polypodium, Acrostichum, Asplenium, and Pteris. Some of them are 
wrappers, such as Ficus with 400 species, Piper with 600, Phyl- 
lanthus with 400-500, Croton 450. ut many of these large 
cosmopoli ra are Dicotyledons of shrubby or arborescent 
an gen y or ar 
habit, with insect-fertilised hermaphrodite flowers, a distinct calyx 
and corolla, and showy scented petals. Loranthus, with 3800 
Commelina, Dioscorea, Dalechampia, Andropogon, Scleria, Kyllingia, 
Mimosa, Jussiga, Homalium, and many other : i 
Wiety-spreap Specms.—The marked tendency to uniformity 
in general character which is shown by the flora of the whole 
tropical zone is further illustrated by the fact that a considerable 
r 
which are most largely represented are Gramineae and Cyperacee 
in Monocotyledons, and, in Dicotyledons, Composite, Leguminosae, 
and Malvaceae. 
