curator of the Botanic Gardens, carefully observed the various
tribes of men therein employed during a considerable period,
and no one has sent me such full and valuable details.
The habit of accurate observation, gained by his botanical
studies, has been brought to bear on our present subject.
For Ceylon I am much indebted to the Rev. S. O. Glenie for answers
to some of my queries.

Turning to Africa, I have been unfortunate with respect to the negroes,
though Mr. Winwood Reade aided me as far as lay in his power.
It would have been comparatively easy to have obtained information
in regard to the negro slaves in America; but as they have long
associated with white men, such observations would have possessed
little value. In the southern parts of the continent Mrs. Barber
observed the Kafirs and Fingoes, and sent me many distinct answers.
Mr. J. P. Mansel Weale also made some observations on the natives,
and procured for me a curious document, namely, the opinion,
written in English, of Christian Gaika, brother of the Chief Sandilli,
on the expressions of his fellow-countrymen. In the northern regions
of Africa Captain Speedy, who long resided with the Abyssinians,
answered my queries partly from memory and partly from observations
made on the son of King Theodore, who was then under his charge.
Professor and Mrs. Asa Gray attended to some points in the expressions
of the natives, as observed by them whilst ascending the Nile.

On the great American continent Mr. Bridges, a catechist
residing with the Fuegians, answered some few questions
about their expression, addressed to him many years ago.
In the northern half of the continent Dr. Rothrock attended to the
expressions of the wild Atnah and Espyox tribes on the Nasse River,