b. That in some groups (and sometimes in particular islands) the identity of the darker and lighter-coloured population is beyond a doubt; coinciding, as it does, with such differences.
c. That transitional forms occur where it is wholly gratuitous to assume the influence of intermixture.
With this opinion our view of the relations between the continuous Kelænonesian areas and the areas of the mixed population would be as follows:—
a. That at a period anterior to the development of the proper Malay and Polynesian characters of the typical Protonesians, New Guinea and Australia were peopled from the Moluccas and Timor respectively; the immigrants having a type which might lose or gain Kelænonesian characters according to circumstances.
b. That the conditions of Protonesia and Polynesia favoured the change from dark to fair; those of New Guinea and Australia from fair to dark.
I will now add a remark of Mr. Blaxland from Mr. Jukes's Voyage of the Fly, which will further illustrate this position:—"The geographical boundary of the Papuan islander is precisely coincident with that of the north-west monsoon. This wind, from the months of November to March inclusive, is the prevalent one over all the space extending from the equator to 10° or 15° south latitude, and in longitude from Sumatra to the Fejee Islands. It is sometimes experienced to the west of Sumatra as far as the north of Madagascar, and it sometimes also extends to the east of the Fejee Islands into the Pacific Ocean; but these extensions are irregular, and its usual eastern boundary is precisely that of the Papuan race before described. Mr. Blaxland deduces from this fact, coupled with the little skill of that race in navigation, the inference, that they have travelled from the west into the Pacific Ocean, and extended their migration only as far as the monsoon allowed them."[84]
This gives us the following theory:—
1. That Kelænonesia was peopled when navigation was so much in its infancy as for the Protonesians to be limited in their migrations by the north-west monsoon.
2. That Polynesia was peopled when it was sufficiently advanced for the same people to be independent of it.