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Darwin Correspondence Project

From William Marshall1   2 June 1875

Weimar

2 Juni 1875.

Sehr geehrter Herr!

Empfangen Sie meinen aufrichtigen Dank für Ihren freundlichen Brief und gütige Sendung.2 Die Feder ist ungemein interessant und sehe ich in ihr eine directe Bestätigung meiner Hypothese. Es ist offenbar ein Rückschlag, sie besitzt einen wahren (keinen scheinbaren, wie die Casuarfedern) Afterschaft und der Hauptschaft seinerseits ist, und dies zwar analog den Casuarfedern, veraestelt das heist, statt dass, wie sonst nur ein Radius entwickelt ist, finden sich deren drei.3 Es ist zugleich von grossem Interesse zu sehn, wie Domestication in relativ kurzer Zeit Geschöpfe zu Rückschlägen bringen kann. Wichtig wäre mir zu wissen ob es eine Rückenfeder ist. Ich vermuthe dass.—4

Demnächst werde ich das Vergnügen haben Ihnen eine grössere Abhandlung über Kieselspongien (Hexactinelliden) zu übersenden.5 Für die Selectionstheorie liefert sie freilich wenig Possitives, desto mehr verspreche ich mir in dieser Richtung von einer Arbeit, mit der ich freilich noch sehr beschäftigt bin, über die Haut der Schmetterlingsraupen, besonders über die Giftapparate;6 die Zahl und die stufenweise Rückbildung zu rudimentaeren Organen (z.B. bei allen versteckt in Holz, unter Steinen etc lebenden Raupen) ist hier geradezu erstaunlich

Sobald ich, wenn Sie erlauben, die Feder zum Gegenstande einer Arbeit gemacht haben werde, werde ich Ihnen dieselbe möglichst unverletzt zurücksenden.7

Mit wahrer Hochachtung | Ihr ergebner | William Marshall

CD note:

Keep feather— 8

Back of Bird?

Written for more—

Some time before they will arrive

How often occur? & Part of body

& all particulars

Your interesting [above del ‘new’] publication [‘seems’ del] promises to be very interesting

Footnotes

For a translation of this letter, see Appendix I.
See letter to William Marshall, 29 May 1875. CD had sent Marshall an ostrich feather that he had received from Thomas François Burgers.
Marshall had sent CD a copy of the journal Zoologische Garten with his article on the juvenile plumage of ostriches and the relation of the feathers of the Ratitae to those of the Carinatae (Marshall 1875a; letter to William Marshall, 29 May 1875). Ratitae and Carinatae were major divisions of birds characterised respectively by the absence or presence of a carina or keel bone on their sternum. The carina makes flight possible by anchoring the wing muscles (see T. H. Huxley 1867). Marshall had hypothesised that the contour (body) feathers of cassowaries and emus could be understood not as having a shaft and aftershaft (or afterfeather) of nearly equal size, but rather as having two feathers sprouting from the same shaft, while the ostrich feather had a single shaft with only one feather (ibid., p. 126). Cassowaries (genus Casuarius) are ratites native to New Guinea and northern Australia; emus (Dromaius novaehollandiae) are Australian ratites.
Marshall evidently considered the aftershaft to be a primitive feature, which, he believed, domesticated ostriches possessed in contrast to wild ones, which lacked it. In flying birds, an aftershaft is more common on contour (body) feathers than on flight feathers, and such feathers typically provide insulation.
CD’s copy of Marshall’s study of the Hexactinellida (glass sponges; Marshall 1875b) is in the Darwin Pamphlet Collection–CUL.
No publication by Marshall on this topic has been identified.
Marshall did not publish on the feather; CD evidently told him to keep it (see n. 8, below).
CD’s annotations are notes for his reply to Marshall, which has not been found.

Bibliography

Huxley, Thomas Henry. 1867. On the classification of birds; and on the taxonomic value of the modifications of certain of the cranial bones observable in that class. [Read 11 April 1867.] Proceedings of the Zoological Society of London (1867): 415–72.

Translation

From William Marshall1   2 June 1875

Weimar

2 June 1875.

Most honoured Sir!

Please accept my sincere thanks for your friendly letter and the kind gift.2 The feather is uncommonly interesting and I see in it a direct confirmation of my hypothesis. It is obviously an atavism, it has a true (not apparent one like the Cassowary feather) aftershaft and the main shaft for its part is, and this really is analogous to Cassowary feathers, branched, that is, instead of only one radius developing, here three are to be found.3 It is also very interesting to see that domestication can cause creatures to revert in a relatively short time. It would be important for me to know if it is a feather from the back. I would think so.—4

Soon I will have the pleasure of sending you a larger treatise on siliceous sponges (Hexactinellida).5 For the theory of selection they afford little support, to be sure, but I have far higher hopes in this direction for a work with which I am still busy, though, on the skin of caterpillars, particularly the poison apparatus;6 the number and step-by-step regression to rudimentary organs (e.g. in all caterpillars that live hidden in wood, under stones, etc) is downright astounding.

As soon as I have, with your permission, used the feather as the subject of a work, I will return the same in as pristine a state as possible.7

With true respect | Your devoted | William Marshall

Footnotes

For a transcription of this letter in its original German, see pp. 213–14.
See letter to William Marshall, 29 May 1875. CD had sent Marshall an ostrich feather that he had received from Thomas François Burgers.
Marshall had sent CD a copy of the journal Zoologische Garten with his article on the juvenile plumage of ostriches and the relation of the feathers of the Ratitae to those of the Carinatae (Marshall 1875a; letter to William Marshall, 29 May 1875). Ratitae and Carinatae were major divisions of birds characterised respectively by the absence or presence of a carina or keel bone on their sternum. The carina makes flight possible by anchoring the wing muscles (see T. H. Huxley 1867). Marshall had hypothesised that the contour (body) feathers of cassowaries and emus could be understood not as having a shaft and aftershaft (or afterfeather) of nearly equal size, but rather as having two feathers sprouting from the same shaft, while the ostrich feather had a single shaft with only one feather (ibid., p. 126). Cassowaries (genus Casuarius) are ratites native to New Guinea and northern Australia; emus (Dromaius novaehollandiae) are Australian ratites.
Marshall evidently considered the aftershaft to be a primitive feature, which, he believed, domesticated ostriches possessed in contrast to wild ones, which lacked it. In flying birds, an aftershaft is more common on contour (body) feathers than on flight feathers, and such feathers typically provide insulation.
CD’s copy of Marshall’s study of the Hexactinellida (glass sponges; Marshall 1875b) is in the Darwin Pamphlet Collection–CUL.
No publication by Marshall on this topic has been identified.
Marshall did not publish on the feather; CD evidently told him to keep it (see n. 8, below).

Bibliography

Huxley, Thomas Henry. 1867. On the classification of birds; and on the taxonomic value of the modifications of certain of the cranial bones observable in that class. [Read 11 April 1867.] Proceedings of the Zoological Society of London (1867): 415–72.

Summary

Discusses feather as case of evolutionary atavism.

Will soon publish on siliceous sponges

and the skin of caterpillars.

Letter details

Letter no.
DCP-LETT-10006
From
William Adolf Ludwig (William) Marshall
To
Charles Robert Darwin
Sent from
Weimar
Source of text
DAR 171: 48
Physical description
3pp (German) †

Please cite as

Darwin Correspondence Project, “Letter no. 10006,” accessed on 9 July 2020, https://www.darwinproject.ac.uk/letter/DCP-LETT-10006.xml

Also published in The Correspondence of Charles Darwin, vol. 23

letter