RECORD: Darwin, C. R. [Draft pages from the Origin of Species, 1859, pp. 210-14, Chapter 7, 'Instinct']. NHM-MSS-DARA Transcribed by Kees Rookmaaker. (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Scanned by the Natural History Museum (London), transcribed by Kees Rookmaaker, corrections by John van Wyhe 8.2010. RN1

NOTE: With thanks to Judith Magee for providing the images. Compare this draft to the published pages of Origin of species, pp. 210-14.

Editorial symbols used in the transcription:
[some text] 'some text' is an editorial insertion
[some text] 'some text' is the conjectured reading of an ambiguous word or passage
[some text] 'some text' is a description of a word or passage that cannot be transcribed
< > word(s) destroyed
<some text> 'some text' is a description of a destroyed word or passage
Text in small red font is a hyperlink or notes added by the editors.

Reproduced by permission of the Trustees of the Natural History Museum (London) and William Huxley Darwin.


[237 recto]

Sect 7. Instincts

as to corporeal As to the bodily organs. Changes of instinct may sometimes be facilitated by instances occurring of very the same species having, though the cases are same case, different instincts at different periods of life, or time of the year, or when placed under different circumstances &c; in which case either one instinct or the other being might be preserved by natural selection: and such cases of diversity of instinct in the same species can be shown to occur in nature.)

(Again, as in the case of corporeal structure, & conformably with our theory, the instinct of each species is good for itself, but not exclusively has has never, as far as we can judge, been produced for the exclusive good of others.
(a) In case In some few cases can certain instincts be cannot be considered as absolutely perfect: but as details on these heads are in not indispensable they shall not be here given.

As some degree of variation in instincts under a state of nature, in the & the inheritance of such variations, is the indispensable foundation for natural selection to act on; it as is highly necessary almost would be highly adviseable here here to give such instances of variation; but want of space here prevents me. I can only say that variations certainly do occur; for instance in the migratory instincts of

[237 verso]

[(a)]1 One of the strongest instances of an animal performing an action for the apparently for the sole good of another, with which I am acquainted, is that of Aphides voluntarily yielding their sweet secretions excretions to Ants: that they do so voluntarily, the following facts show. I removed all the ants from attending on a group of aphides on a dock-plant; & prevented their visits for during several hours. revisiting them; By which time After this period, I was sure that the Aphides would want to excrete: I then watched them for some time through a lens, & not one excreted; & I then tickled & stroked them with a hair fixed to a han in the same manner as nearly like far as I could, as the ants do with their antennæ; but not one excreted.

Then As soon, however, as I then allowed an ant to visit them; & after hastily examining them he l immediately this ant by the eager way it ran over to whole lot of above a dozen, seemed aware what a rich flock it had discovered, it then began to play with its antennae on [their] abdomens first of one aphis & then of another; up to 15 or 16 & each aphis immediately, came after the other as soon as it felt the antennæ & there were above a dozen. immediately lifted up its abdomen & excreted a limpid drop of the sweet juice, which was devoured by the ant. Even the quite young aphides behaved in this way manner», showing me that it was instinct & not experience. But as the excretion is extremely viscid, I do not doubt that it is a convenience to the aphides to have it removed. )( Although I do not believe that any animal in the world performs an action for the exclusive good of another, yet

1 Top left part of page is torn off. The insertion relates to the note (a) of the previous page.

(238

Sect 7. Instincts

animals, both in extent & direction or in not migrating at all. So it is with the nests of birds, partly dependent on the situations chosen, or on the country inhabited & on its temperature, but often from causes wholly unknown to us: Audubon gives several remarkable cases of differences of nests in the same species in the Northern & Southern parts of the United States. So it is with fear directed towards particular enemies; which fear is certainly an instinctive quality, as may be seen in nestling birds, though it is strengthened by evil experiences in themselves & sometimes by seeing fear of the object enemy in other animals. We may assume see a case of [wholly] acquired, yet apparently instinctive fear others in our own country in the universally greater wildness of all our large birds, than of our small birds, which are less persecuted by man. Nothing but long-continued persecution can have given wildness to all our larger birds; for in In uninhabited islands, large birds are not more fearful than small; & our most the magpies so wary magpies in England is tame in Norway, as is the Hooded Crow in Ægypt.) (That the general disposition of animals individuals of the same species, born in a state of nature, are is extremely diversified, can be shown by an abundance a multitude of facts. Many Several cases, also could be given of odd & aberrant occasional & strange habits in certain species could be given, which might if advantageous to the species give rise through natural selection to quite new instincts. But I am well aware that these general statements,, without any the facts given in detail, can produce but a most feeble effect on the reader's mind. I can only repeat my assurance, that I do not speak without good evidence.)

(239

Sect 7. Instincts

(The possibility or even probability of inherited variations of instinct in a state of nature will be strengthened by briefly considering the case of a few cases in not yet our domestic animals. We shall, also, thus be enabled to see the respective parts which the selection habit & the selection of so-called accidental variations have played in modifying these mental qualities.

A number of curious & authentic instances could be given of the inheritance of all shades of dispositions & of tastes & likewise of the inheritance of the oddest tricks associated with certain frames of mind or periods of time. But let us look to the familiar case of the several breeds of dogs: it cannot be doubted that some young pointers (I have myself seen a most striking instance) will sometimes point & even back other dogs, the very first time that they are out taken out: retrieving is certainly in some degree inherited by retrievers, & a tendency to run round, instead of at a flock of sheep, by shepherd dogs.

I cannot see that these actions, performed by each breed without experience, by the young, & in nearly the same manner by each individual, performed with eager delight by each breed & without the end namely the being known to the animal, — for the young pointer can no more know that he points for the gr use of to aid man, than does the white butterfly know why it lays its eggs on the leaf

(240

Sect 7. Instinct

of the cabbage,— I cannot see that these actions differ essentially from true instincts. If we were to see one kind of wolf, when young & without any training, as soon as it scented its prey, standing motionbless like a statue; & then slowly approach crawl forwards with a peculiar gait; & another kind of wolf instead of rushing at, its round, instead of at its prey a herd of deer & driving them to a distant point, we should assuredly call these actions instinctive. These domestic instincts, as they may be called, are certainly far less fixed or invariable than natural instincts; but they have been acted on by far less rigorous selection, continued for an incomparably shorter period, & under less fixed conditions of life.

How strongly these domestic instincts & dispositions are inherited & how c & how curiously they become mingled is well shown when different breeds of dogs are crossed. Thus it is known that a cross of a bull-dog has affected for many generations the disposition courage & obstinacy of greyhounds; & a cross of this latter breed will long give for generations to a family of to the shepherd dogs a tendency to hunt hares. These domestic instincts, when thus tested by crossing, behave like natural instincts, which become curiously blended & long show for a long period traces of either parent:


This document has been accessed 1613 times

Return to homepage

Citation: John van Wyhe, editor. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

File last updated 2 July, 2012