422 Proceedings of the Royal Physical Society. 
it is best to be guided by linguistic facts; but, as according to 
Cust there are no less than 438 languages and 153 dialects 
spoken in Africa, such a classification is for present purposes 
impossible, and therefore I adopt Miller’s classification of 
distinct groups, as follows :—(1) The Semitic family, along 
the north coast of Africa and of Abyssinia; (2) the Hamitic 
family, who dwell mainly in the Sahara, Morocco, Algeria, 
Egypt, and in the Galla and Somali districts; (3) the Fulah 
and Nuba groups, who live in the western central and eastern 
Soudan; (4) the Negro groups, in the western and central 
Soudan, in Upper Guinea and the Upper Nile region; (5) the 
Bantu family, everywhere south of 4° N. lat., except in the 
Hottentot domain; (6) the Hottentot group, in the extreme 
south-western corner of Africa, from the Tropic of Capricorn 
to the Cape; (7) the Tikki-Tikkis and Akkas, living in 
scattered groups to the north of the equator. 
A few sentences are necessary with regard to the general 
characteristics of these people, to show their possible predis- 
position to certain diseases, their immunity from others. 
The inhabitants of Africa have, on the whole, a well-developed 
muscular system. Mentally they are like children, easily 
amused and easily roused to passion. They possess innate 
capabilities of high education, but it is a mistake to suppose 
that the average Negro child can be educated up to the 
European standard. Till the age of fourteen he will probably 
distance a European child in almost all brain work, but after 
this age the light-skinned Caucasian shoots ahead of the 
dusky child of the Tropics. As a rule, at least three genera- 
tions are necessary to develop the Negro to our mental 
standard. Owing to the climatological factors to which I 
have referred, the natives possess a lethargic constitution. 
Nature being so bountiful, they have no incentive to 
strenuous manual labour. But there is a marked difference 
between the inhabitants of the mountainous regions of the 
Tropics and those inhabiting the low-lying plains. For 
instance, the inhabitants of the northern and higher parts of 
Uzinza are far more strongly built and energetic than the 
Wazinza who inhabit the southern and lower parts of the 
country. Such, at any rate, was the opinion of Speke, aud I 
