[215]

(215

Sect VI. Organs of little apparent importance

Organs of little apparent importance.—As natural selection acts solely by preservation & destruction or by by life & death; I  have often sometimes felt almost sur much difficulty though of a very different kind, in understanding the origin of simple parts, the structure of which does not seem of high importance to the welfare of its possessor, (a) or gives an idea as in the case of the most perfect perfect & complex organs, such as the eye.

In the first place we are much too ignorant of the whole economy of every living thing any one organism. to say what slight modifications are important or not. In a former chapter, I have given some instances of most trifling differences, such as the down on fruit, & the colour of its flesh, which from being correlated with some constitutional differences, what would might assuredly be acted on by natural selection. The tail of the gir affe looks like an artificially constructed fly-flapper: & it seems at first almost incredible that this could have been formed adapted for its present purpose by successive slight modifications, each better & better, for so trifling a purpose as driving away flies: yet we should pause in being too positive on this head, when we know that the distribution & existence of cattle & other animals in South America actually depend on the attacks of flies; insects; that if any race would be were formed, which could well better defend itself from these small enemies, it would be be enabled to range into new pastures. In many many such cases, we should remember that flies, for instance, do not directly cause the destruction of the ca larger animals, but by incessantly harassing them, reduce reduce

[215(a)]

(a) I have sometimes felt as much difficulty, though of a very different kind, on this head, as in the case of

[there are pin holes where this is attached to the back of folio 215]

[216]

(216

Sect VI. Organs of small importance

their strength, so that they are more subject to disease, or less enabled in a coming dearth to search for food, or to escape from beasts of prey […]

[p. 196:]

Seeing how important an organ of locomotion the tail is in most aquatic animals, its general presence & use for many purposes in so many land animals, which betray in their lungs or modified swim-bladder their aquatic origin, may perhaps be accounted for […]

[…] & finally, amongst animals, being a

[page] 65

The Property of a Descendant of Charles Darwin

[sales catalogue not transcribed here but available in the image view]

[page] 67

141 DARWIN (CHARLES) TWO PAGES FROM THE AUTOGRAPH MANUSCRIPT OF 'THE ORIGIN OF SPECIES', FIRST EDITION, COMPRISING THE OPENING OF THE SECTION ON "ORGANS OF LITTLE APPARENT IMPORTANCE [AS AFFECTED BY NATURAL SELECTION]" FROM CHAPTER VI, beginning:

Organs of little apparent importance.-As Natural Selection acts solely by preservation & destruction or by by [sic] life & death; I have sometimes felt much difficulty in understanding the origin of simple parts, the structure of which does not seem of high importance to the welfare of its possesor. I have sometimes felt as much difficulty, though of a very different kind, on this head, as in the case of the most perfect & complex organs, such as the eye . . .

stating that we are much too ignorant of "the whole economy of any one organism" to say what slight modifications are important or not, instancing the fly-swatter tail of the giraffe:

. . . The tail of the giraffe looks like an artificially constructed fly-flapper: & it seems at first incredible that this could have been adapted for its present purpose by successive slight modifications, each better & better, for so trifling a purpose as driving away flies: yet we should pause in being too positive on this head, when we know that the distribution & existence of cattle & other animals in South America actually depend on the attacks of insects; that if any [?] race were formed, which could better defend itself from these small enemies, it would be enabled to range into new pastures. In such cases, we should remember that flies, for instance, do not directly cause the destruction of the larger animals, but by incessantly harassing them, reduce their strength, so that they are more subject to disease, or less enabled in a coming dearth to search for food, or to escape from beasts of pray . . .

postulating that organs now of little importance may in some cases have been of high importance to an ancestral form and alluding to his well-known observation that the lung is evolved from the fish's swim-bladder (". . . at the same time any actually injurious deviations in its structure would be guarded against by natural selection . . ."):

. . . Seeing how important an organ of locomotion the tail is in most aquatic animals, its general presence & use for many purposes in so many land animals, which betray in their lungs or modified swim-bladder their aquatic origin, may perhaps be accounted for . . .

Darwin goes on to observe that we may sometimes attribute importance to characters of really very little importance, which may have appeared from quite secondary causes (". . . that is not directly through natural selection . . ."), such as climate, food, re-appearance through reversion, and the correlation of growth, 2 closely-written pages, on blue-grey paper, tall folio, one passage of two-and-a-half lines on a slip of paper pinned to the verso of the first page, with numerous revisions and deletions, each leaf numbered by Darwin at the top right-hand corner ("215" and "216"), the first page headed by him "Sect VI. Organs of little apparent importance" the second "Sect VI. Organs of small importance", the second page breaking off: "& finally, amongst animals, being a"

*** The importance in the history of ideas of the publication on 24 November 1859 of On the Origin of Species by Means of Natural Selection can hardly be exaggerated. The present manuscript is for pages 194-196 of the first edition. Darwin had sketched his first version of his theory of evolution by Natural Selection in 1842, and developed this into a fuller essay in 1844. He did not embark on what was intended as a definitive exposition until 1856, but his work was interrupted by the arrival of Wallace's letter of 18 June 1858, in which was outlined a theory remarkably close to his own. This prompted the presentation of a joint paper to the Linnean Society on 1 July. Darwin began work on The Origin of Species, in effect an abstract of the larger, abandoned work, on 20 July. By Christmas he had written 330 pages, including the present ones, numbers 215 and 216. Some of the material in these two pages can be found in the longer work (cf. Charles Darwin's Natural Selection, edited by R. C. Stauffer, 1975, p. 376ff.). They differ from the published text only in matters of phrasing, something which Darwin worked heavily on at proof stage (see for example his letter to his publisher John Murray of 14 June 1859: "I find the style incredibly bad, and most difficult to make clear and smooth. I am extremely sorry to say, on account of expense, and loss of time for me, that the corrections are very heavy, as heavy as possible", Life and Letters, II, p. 159). The present text was little altered in later additions, apart from a passage at line eleven and the section heading, which was expanded (as given at the beginning of this entry in parentheses).