412 
ISLAND LIFE. 
[part II. 
fifty are endemic, twenty-two are Asiatic but not African, while 
twenty-eight are African but not Asiatic. This implies that the 
more ancient connection has been on the side of Africa, while 
a more recent immigration, shown by identity of species, has 
come from the side of Asia ; and it is probable that when the 
flora of Madagascar is more thoroughly worked out, the same, or 
a still greater African preponderance, will be found in that island. 
A few Mascarene genera are found elsewhere only in South 
America, Australia, or Polynesia ; and there are also a con- 
siderable number of genera whose metropolis is South America, 
but which are represented by one or more species in Mada- 
gascar, and by a single often widely distributed species in 
Africa. This fact throws light upon the problem offered by 
those mammals, reptiles, and insects of Madagascar which now 
have their only allies in South America, since the two cases 
would be exactly parallel were the African plants to become 
extinct. Plants, however, are undoubtedly more long-lived 
specifically than animals — especially the more highly organised 
groups, and are less liable to complete extinction through the 
attacks of enemies or through changes of climate or of physical 
geography ; hence we find comparatively few cases in which 
groups of Madagascar plants have their only allies in such 
distant regions as America and Australia, while such cases are 
numerous among animals, owing to the extinction of the allied 
forms in intervening areas, for which extinction, as we have 
already shown, ample cause can be assigned. 
Curious Relations of Mascarene Plants . — Among the curious 
affinities of Mascarene plants we have culled the following 
from Mr. Baker’s volume. Trochetia, a genus of Sterculiaceae, 
has four species in Mauritius, one in Madagascar, and one in 
the remote island of St. Helena. Mathurina, a genus of Turner- 
aceae, consisting of a single species peculiar to Rodriguez, has 
its nearest ally in another monotypic genus, Erblichia, confined 
to Central America. Siegesbeckia, one of the Compositae, con- 
sists of two species, one inhabiting the Mascarene islands, the 
other Peru. Labourdonasia, a genus of Sapotaceae, has two 
species in Mauritius, one in Natal, and one in Cuba. Neso- 
genes, belonging to the verbena family, has one species in 
