skip to content

Darwin Correspondence Project

From Gerhard Rohlfs   6 June 1871



Dear Sir,

Your last work as also the precedents I read with very much interest.1 I beg you to accept the few remarks I made as a little proof of high esteem I have for you. Your Theorie gains every day more adherents.

I have been nearly ten years in Africa crossing over the continent from Tripolis by the lake of Tshad2 to the coast of Guinea. I should be glad if I could fournish still more facts to your wise doctrine.

Yours very faithfully and obediently | Dr. Gerhard Rohlfs | medalist of the r. geogr. Society of London.3 I beg to excuse my bad englisch being german.

adr. Dr G. Rohlfs Weimar in Germany.

t. p. 149. The sheeps fournished with wool of North-Africa lose the wool as soon as they are driven in the hot oasis of the Sahara. Usualy already after one year the wool change to hair, and the young ones are born with hairs, not with wool. (own experience)4

Mental powers: It is very known that the cats never public to ease themselves, but they dig a hole, and afterwards they cover it by scraping something over. I believe this is bashfulness.

Being in Rhadames5 in 1865, I had a dog which never bite strangers once admitted into my house. One day Touareg6 being my guests and sitting close to me occupied to eat, the dog from behind sneak near and bite one of the Touareg very severly. I believe envy was the motive.

t. I. p. 216.7 I am convinced, that in Europe the half of the caucasians, if the they had black colour and curled hair, would resemble to Negros. On the other hand I observed very nomerous negros which would resemble entirely white men, if they only were endowed with long hair and white skin.

t. I. p. 221. I observed that in the large oasis of Draa, Tafilet and Tuat (great Sahara of Africa) which are inhabited exclusive by hybridous-people (Mischlingsvolk) procreated partly by white Arabians and Barbarians, partly by black negros of the Haussa- Bornu- and Wadai-family—that the fertility of this hybridous people was extraordinary great.8

t. I. p. 224. I observed in Africa very frequent, that by marriage of a black with a white either a complete black or complete white childe was produced. Sometimes a red child, but sometimes was produced a black and white child i.i. parts of the scin were black, parts white, last case was very seldom.9

t. I. p. 242. weight must also be given etc etc. I thing the residence of the Dutch families in Southern-Africa could not be occasion to darken the skin. The dutchmen stay there between the 30o and 35o S.L. This is corresponding in climatic reference to 35o–40o N.L. It is known that the southern hemisphere has a much colder climat on account of the more waterish character, than the northern. In this latitude live in Europe greecs, Italians, Spaniards etc, to whom we give no darker complexion than that deduced from sunshine. In northern Africa the arabians and Barbarians are very dark (teint basané)10 as soon as they are nomades; but they are very white as soon as they are dwelling in towns (the maures, Mauren, Mooren, los moros) it is, when they are not exposed to sunshine.11

t. II. p. 224. Every one quoted by you has never been in the great Sahara. I observed (I crossed the Sahara tree times) that at least there are so many animals in the desert having different colour than others with corresponding colour of the terrain or ground.12

t. II p. 350. I have had the opportunity to state the same sentiments of beauty as Mr. W. Reade. Namely in Bornu, in Haussa and in countries inhabited by the Pullo-tribes I found the same sentiments and ideas of beauty as ours.13

CD annotations

1.1 Your … great. 9.5] crossed pencil
5.1 t. … experience) 5.4] ‘Sheep long wool in Sahara’ pencil
10.1 t. … seldom. 10.4] crossed ink
11.1 t. … sunshine. 11.10] crossed pencil
12.1 t. … ground. 12.4] crossed ink
13.1 t. … inhabited 13.2] ‘see also top of first page’;14 ink ‘☞’ pencil
Top of letter: ‘Sahara not so well protected as Tristram says’ pencil


CD’s most recently published work was Descent.
Tschad-See is the German for lake Chad, a large shallow lake whose size varies seasonally, which is mainly in the present Republic of Chad and partly in north-east Nigeria and north Cameroon. The lake was considerably larger in the nineteenth century (Columbia gazetteer of the world).
Rohlfs was awarded the patron’s gold medal of the Royal Geographical Society of London on 25 May 1868 (Proceedings of the Royal Geographical Society of London 12 (1867–8): 210).
In Descent 1: 149, CD discussed the possibility that early humans might have lost body hair through living in a hot climate.
Rhadames (now Ghudamis) is a township in western Libya near the Algerian and Tunisian borders (Columbia gazetteer of the world).
The Touareg (or Tuareg) are a nomadic people of the Sahara.
In Descent 1: 216–50, CD discussed racial differences in humans and the debate about whether different races should be considered distinct species.
CD discussed accounts of reduced fertility in people of mixed racial background in Descent 1: 221–3. By ‘Barbarias’, Rohlfs probably means Berbers; that is, the indigenous people of North Africa. Haussa (now Hausa) is the name of a people native to Niger as well as of the former African kingdom in that area. Bornu and Wadai were African kingdoms in the regions of modern Nigeria and Chad (EB). CD added Rohlfs’s comments on the fertility of mixed races in Descent 2d ed., p. 171 n. 12.
In Descent 1: 224, CD discussed the predominance of colour blending in the children of parents of different colours as an argument against blackness being a sudden variation or sport, such sudden variations being usually subject to ‘all-or-nothing’ inheritance.
Teint basané: tanned complexion (French).
In Descent 1: 241–2, CD discussed the relation between skin colour and climate, but did not specifically refer to sun exposure as a factor.
CD’s remarks on protective coloration (Descent 2: 224–5) were about birds. His source was Henry Baker Tristram, who spent several months in parts of the Sahara south of the Saharan Atlas mountains (Tristram 1860). Rohlfs was the first European to travel in the Libyan desert (NDB). In Descent 2d ed., p. 490 n. 50, CD added Rohlfs’s comment.
William Winwood Reade had expressed the opinion that inhabitants of the west coast of Africa and Europeans shared similar ideas on beauty (Descent 2: 350). CD had argued that different groups had different standards of beauty (Descent 2: 343–50). CD added Rohlfs’s comments on beauty in Descent 2d ed., p. 582.
The end of the last sentence of Rohlfs’s letter, ‘by the Pullo-tribes … beauty as ours.’ is written at the top of the first page.


Columbia gazetteer of the world: The Columbia gazetteer of the world. Edited by Saul B. Cohen. 3 vols. New York: Columbia University Press. 1998.

Descent 2d ed.: The descent of man, and selection in relation to sex. By Charles Darwin. 2d edition. London: John Murray. 1874.

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

EB: The Encyclopædia Britannica. A dictionary of arts, sciences, literature and general information. 11th edition. 29 vols. Cambridge: Cambridge University Press. 1910–11.

NDB: Neue deutsche Biographie. Under the auspices of the Historical Commission of the Bavarian Academy of Sciences. 26 vols. (A–Vocke) to date. Berlin: Duncker & Humblot. 1953–.


Various observations from his experience in Africa relevant to Descent.

Fertility of hybrids of blacks and whites.

Protective coloration of Sahara animals.

Natives’ ideas of female beauty.

Letter details

Letter no.
Gerhard Friedrich (Gerhard) Rohlfs
Charles Robert Darwin
Sent from
Source of text
DAR 89: 183–4
Physical description
3pp †

Please cite as

Darwin Correspondence Project, “Letter no. 7805,” accessed on 18 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 19