The facts on which these statements rest, will be found more fully detailed in the Author's Presidential Address to the Entomological Society of London for the year 1871.
Quarterly Journal of the Geological Society, 1874, p. 494.
Dr. Schweinfurth has accurately determined the limits of the sub-region at the point where he crossed the watershed between the Nile tributaries and those of the Shari, in 4½° N. Lat. and 28½° E. Long. He describes a sudden change in the character of the vegetation, which to the southward of this point assumes a West-African character. Here also the chimpanzee and grey parrot first appear, and certain species of plants only known elsewhere in Western Africa.
There are also some special resemblances between the plants of Madagascar and South Africa, according to Dr. Kirk.
As so many typical Malay groups are absent only from the Philippines, I have adopted the term "Malaya," to show the distribution of these, using the term "Indo-Malaya" when the range of the group includes the Philippines. This must be remembered when consulting the tables of distribution at the end of this chapter.