FIRST ORDINARY MEETING. 21 
atmosphere, where the temperature will be high, but will vary little. 
Though the rays of the sun will descend vertically upon him, yet their 
power will be diminished by the vapour contained in the air, and 
he will not need so dense a pigment to protect him as the inhabitants 
of other tropical regions. Add to this, that a thin epidermis will 
facilitate the perspiration which a moisture-laden atmosphere tends 
to check, and we come to the conclusion that the natives of such 
countries will be distinguished by comparatively fair complexions. 
As an example of a moist tropical climate we may take the valley 
of the Amazons and point to the fact that its aborgines are lighter 
in colour than those of rainless Peru. 
V.—On the contrary in a rainless tropical climate, or in one 
with a well-marked dry season, the rays of a vertical sun will con- 
tinually or for considerable periods descend in all their power, and 
the densest pigment and the thickest scarfskin will be needed. In 
rainless Nubia, for example, the inhabitants, whether of Semitic, 
Hamitic, or Negro stock, are alixe black. 
The part of Africa south of the Great Desert, will exemplify 
the case of a tropical climate with a dry season. This immense 
region consists essentially of a strip of low coast land, and an im- 
mense level central depressed surface with a more or less elevated 
rim surrounding it. The inhabitants of the coast and the central 
depression are very black, those of the rim lighter in color. Dr. 
Livingstone attributed this to the greater humidity of the lower 
regions. But it is obvious from theoretical considerations that the 
elevated rim must be more humid than any other part of the contin- 
ent. During the dry season, the sea-breezes, when they strike the 
eoast, will be raised in temperature and consequently deposit no 
moisture until cooled by being forced upward when they come against 
some elevated land. The meterological observations of travellers 
show the facts to accord with this view. 
There are black men in Africa, in India, and in Australia and 
some of the adjacent islands, because these countries all have long, 
pronounced dry seasons. Owing to the peculiar formation of the 
continent of America, its tropical regions are, for the most part, very 
humid, and consequently very dark natives are found within them 
only in Peru, which possesses a very dry climate. 
An immense number of facts might be adduced in support of this 
theory ; but there are some which it fails to explain. Nevertheless, 
