and the beautiful weevils forming the genus Eupholus. Among butterflies we
have the genera Mynes, Hypocista, and Elodina, and the curious eye-spotted
Drusilla, of which last a single species is found in Java, but in no other of the
western islands.
The facilities for the distribution of plants are still greater than they are for
insects, and it is the opinion of eminent botanists, that no such clearly-defined
regions pan be marked out in botany as in zoology. The causes which tend to
diffusion are here most powerful, and have led to such intermingling of the
floras of adjacent regions that none but broad and general divisions can now be
detected. These remarks have an important bearing on the problem of dividing
the surface of the earth into great regions, distinguished by the radical difference
of their natural productions. Such difference we now know to be the direct result
of long-continued separation by more or less impassable barriers; and as wide
oceans and great contrast: of temperature are the most complete barriers to the
dispersal of all terrestrial forms of life, the primary divisions of the earth should
in the main serve for all terrestrial organisms. However various may be the
effects of climate, however unequal the means of distribution; these will never
altogether obliterate the radical effects of long-continued isolation; and it is my
firm conviction, that when the botany and the entomology of New Guinea and
the surrounding islands become as well known as are their mammals and birds,
these departments of nature will also plainly indicate the radical distinctions of
the Indo-Malayan and Austro-Malayan regions of the great Malay Archipelago.