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 persprration 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. 



Y. — 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 alike 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 

 coast, 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 

 tfcheory ; but there are some which it fails to explain. Nevertheless, 



