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Darwin Correspondence Project

From George P. Bissell   10 February 1870

Salem, Oregon, United States of America,

Feb, 10th 1870.

Charles Darwin; M.A.

Dear Sir.

I have just finished reading your first and smaller work, on The Origin of Species,1 &c. and would herein express my pleasure at the natural and scientific view of the subject therein advocated.

In the interest of Science, I suppose that I am justified in addressing you, for the purpose of calling your attention to some few facts, which possibly bear affirmatively on the points discussed.

First, I would call attention to the Humming birds of Puget Sound. Your map will show you that Puget sound lies near the Pacific Ocean, adjacent to Vancouvers Island, British Columbia.2

A description of these Humming-birds will be found among the papers of the Smithsonian Institute.3 I can not indicate more nearly, for I am but a cursory reader, not a special student. Now the particular fact is this, that there are about (40) forty varieties, or species of these birds on the western coast of the continent of America, and only three or four species or varieties on the eastern Coast, notwithstanding that they are birds of passage.4

2d. The Bobolink, or Carolina rice bird, is never seen on the Pacific coast, though very common on the Atlantic coast. It is my impression, but I am not certain, that it is never seen west of the Alleghany Mountains.5 I do not know of any works wherein this is mentioned.

3d I can not find that the American Bison ever ranged east of the Aleghany Mountains, and it is certain that they suddenly passed west of the Mississipi River during the present century, abandoning forever their former range on the East of that river.

At about the same period, they suddenly contracted their range from the west of the Rocky Mountains, over a space of probably about 700 or 800 miles of latitude. This fact again I have never seen mentioned, but from my own observation, and from information derived from old hunters, I know it to be true. And I judge that the contraction on the eastern limit, could not have been caused by the pressure of civilized man on their flank, because we know that the almost simultaneous contraction of the western limit was not induced by such a cause. Records of the contraction of the eastern limit may be found in books.6

4th. A short distance west of the Missouri River the Oak and the Hickory suddenly cease, although they are very plentiful to the eastward.

The same holds true of other plants. The termination is abrupt, but the line of termination is waved.7

5th The Hudson River (in the eastern part of the state of New York) is, and always has been, the eastern limit of the Turkey buzzard, and of the opossum. The same river is also the western limit of some small animals, and of some plants.8 But it is quite singular and striking in the case of the Turkey buzzard. These are facts which you can verify in the reading of an extensive library, especially of American Authors.

I conceive that they have some bearing on the theory which you advance, and offer them solely in the interest of science.

George P. Bissell. M.D.

Charles Darwin M.A. | Down, Broomley, Kent, England

CD annotations

4.5 three or four … mentioned. 5.4] crossed blue crayon
8.1 4th.... is waved. 9.2] crossed blue crayon
Verso of last page: ‘Range of Bison— (Rivers)’ blue crayon


Bissell refers to either the first American edition of Origin (Origin US ed.), or to one of the first five British editions (Origin).
Puget Sound, on the north-western coast of Washington State, is connected to the Pacific Ocean by the Strait of Juan de Fuca; Vancouver Island of British Columbia extends to the north-west (Columbia gazetteer of the world).
The publication has not been identified.
In 1870, a single species of humming-bird (the ruby-throated) was known on the east coast of the United States, and only six (the rufous, callipe, Costa’s, Anna’s, Allen’s, and black-chinned) were known on the west coast north of Mexico (Dennis Paulson, personal communication, Slater Museum of Natural History, University of Puget Sound).
The present distribution of the bobolink (Dolichonyx oryzivorous) extends as far west as eastern and south-central Washington, and eastern Oregon (S. G. Martin and Gavin 1995). The Allegheny Mountains, part of the Appalachian Mountain Range of the eastern United States, extend south-west from central Pennsylvania to south-western Virginia.
Bison or buffalo (Bison bison) once inhabited the mid-Atlantic states, from New York State to Florida, and extended westward to eastern Oregon. They were most plentiful in the Great Plains; however, their numbers diminished notably in the nineteenth century due to hunting and shrinking habitat. On the historic range of bison, and on their nineteenth-century demise, see Lott 2002, pp. 67–76, 167–9, 170–7. For a list of early written accounts on bison, see Garretson 1938, pp. 233–42.
Oak-hickory forests are found only in the eastern half of the United States (Kricher 1998, pp. 60, 82). The Missouri River flows south-east from Montana to its confluence with the Mississippi River north of St Louis. It forms the western boundary of Iowa, beyond which oak-hickory forests are uncommon.
By 1840, the turkey-buzzard or turkey-vulture (Cathartes aura) was said to not have been seen further north or east of New Jersey (Audubon 1840–4, vol. 1, plate 2); it is now widespread throughout the United States. Early European settlers found no American opossums (Didelphis) north of present-day Virginia and Ohio; they have since continued spreading northward from South America (D. W. MacDonald ed. 2006, 1: 16).


Audubon, John James. 1840–4. The birds of America; from drawings made in the United States and their territories. 7 vols. New York: J. J. Audubon. Philadelphia: J. B. Chevalier.

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

Garretson, Martin S. 1938. The American bison; the story of its extermination as a wild species and its restoration under federal protection. New York: New York Zoological Society.

Kricher, John C. 1998. A field guide to eastern forests, North America. 2d edition. Boston: Houghton Mifflin.

Lott, Dale F. 2002. American bison: a natural history. Berkeley, Calif. and London: University of California Press.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Origin US ed.: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. A new edition, revised and augmented by the author. By Charles Darwin. New York: D. Appleton. 1860.


Sends information on the distribution of various species in the U. S.

Letter details

Letter no.
George P. Bissell
Charles Robert Darwin
Sent from
Salem, Ore.
Source of text
DAR 205.3: 261 (Letters)
Physical description
ALS 3pp †

Please cite as

Darwin Correspondence Project, “Letter no. 7101,” accessed on 4 October 2023,

Also published in The Correspondence of Charles Darwin, vol. 18