Ɛpsilon

From Rudolph Riemann1   9 July 1875

Hochgeehrtester Herr!

In Bezug auf Ihr Werk: “Über die Entstehung der Arten” erlaube mir zu Capitel IX Folgendes mitzutheilen:2

Als professioneller Schafzüchter habe ich die Bastardirung von Serinus hortulanus (Girlitz) mit Dryospiza canaria (Kanarienvogel) hauptsächlich zu Klarlegung des Vererbungsgesetzes angestellt.3 Dabei bin ich zu dem von Ihnen bekanntgegebenen Gesetze des “Prosper Lucas” gekommen;4 Ausnahmen finden nur bei hervorragender Individual-Potenz statt, die nach meiner Erfahrung kräftigen Thieren besonders eigen ist.

Mit möglichster Vermeidung aller Inzucht, die ich als Züchter zu hassen weiss, habe ich nun in diesem Jahre verehelicht:

I: Männchen: 3132 Dryospiza 132 Serinus
Weibchen: 1516 dto 116 dto
II: Männchen: 1516 Dryospiza 116 Serinus
Weibchen: 78 dto 18 dto
III Männchen 3132 Dryospiza 132 Serinus
Weibchen 3132 dto 132 dto
IV. Männchen 78 dto 18 dto
Weibchen 3132 dto 132 dto

Aus sämmtlichen dieser Paarungen sind Kinder erzeugt worden und erwachsen.

ich diene hiemit zur Ansicht von, aus beiden Theilen Bastard “Eltern” in

I mit 6164 Dryospiza 364 Serinus
II " 2932 dto 332 dto
III " 3132 dto 132 dto
IV " 5964 dto 564 dto.

Um unter allen Umständen zu dem jetzt schon erreichten Resultate zu kommen, eine neue Art zu bilden, habe ich die Bastardirung durch “Anpaarung” zugleich weiter getrieben und kann ich mit der Ansicht von 6364 Dryospiza m. 164 Serinus dienen, deren Vater Bastard (132 Serinus) u. deren Mutter Dryospiza ist.

Auf Wunsch theile gern alles Nähere mit und bevollmächtige zu jedem beliebigen Gebrauche dieser Mittheilung. Die Thatsachen selbst bin ich jeder Zeit bereit zu beeiden.

Mit vorzüglichster Hochachtung | ganz ergebenst | Rud. Rieman | Breslau, Centralbahnhof 31.

z. Z. auf meiner | Besitzung: | Zell am See, | Herzogthurm Salzburg, | 9. VII. 75.

[Contemporary translation]

Honoured Sir,

With reference to yr. work ‘The Origin’ I permit myself to communicate the following touching Chapt. IX.

Principally with a view to the elucidation of the law of inheritance I, as a professional breeder of sheep, have induced the crossing of Serinus hortulanus (Girlitz) with Dryospiza Canaria (Canarienvogel). Thereby have I arrived at the known law of Prosper Lucas, given by you.— Exceptions only resulted from preponderating individual potency, which according to my experience is especially apt to appear in powerful animals.

I have, in the present year made the following crosses, with all possible avoidance of in & in breeding, which I as a breeder have learnt to dislike.

I: male 3132 Dryospiza 132 Serinus
female 1516 ditto 116 ditto
II: male 1516 Dryo. 116 Ser.
female 78 ditto 18 ditto
III male 3132 Dryo. 132 Ser.
female 3132 Dryo. 132 ditto
IV. male 78 ditto 18 ditto
female 3132 ditto 132 ditto

From every one of these crosses young were bred & grew up.

Hereby I use the following proportions from hybrid parents on both sides: from—

I 6164 Dryos. 364 Serinus
II 2932 — 332 —
III 3132 — 132 —
IV 5964 — 564 —

In order under all conditions to come to the results now already attained—the formation of a new species—I have carried yet further the hybridism by pairing, and I can make use of the proportion 6364 Dryospiza, 164 Serinus, whose father is a hybrid (132 Serinus)& whose mother is Dryospiza.

You may use this how you like   I can vouch for the facts

Rud: Riemann

Zell am See | Herzagthum Salzburg

CD annotations

2.1 Serinus hortulanus 2.2] underl blue crayon
2.2 (Girlitz)] ‘in Bechstein Fringilla serinus Linn.’5 added ink
2.2 Dryospiza canaria] underl blue crayon
1
For a translation of this letter, see Appendix I. A contemporary translation found with the letter is included above.
2
Chapter 9 of Origin 6th ed. was on hybridism.
3
Riemann bred sheep on his estate at Sagschütz near Breslau (now Wrocław in Poland; for more on his theories of sheep breeding, see Riemann 1875). Serinus hortulanus is a synonym of Serinus serinus (the serin). Dryospiza canaria is a synonym of Serinus canaria (the wild canary). Crosses between canaries and finches are briefly mentioned in Origin 6th ed., p. 240.
4
Prosper Lucas is cited in Origin 6th ed., p. 261, on the ‘laws of resemblance’, namely, that offspring tend to resemble both parents even when the parents are of different varieties or species; and that cases in which the offspring more closely resemble one parent are rare in hybrids. CD’s extensively annotated copy of Lucas’s work on heredity (Lucas 1847–50) is in the Darwin Library–CUL (see Marginalia 1: 513–23).
5
Fringilla serinus is a synonym of Serinus serinus. CD had read two works by Johann Matthäus Bechstein (Bechstein 1789–95 and Bechstein 1840), both of which discussed the interbreeding of canaries and finches. CD’s heavily annotated copies are in the Darwin Library–CUL (see Marginalia 1: 38–47).

From Rudolph Riemann1   9 July 1875

Most highly honoured Sir!

Regarding your work: “On the origin of species”, permit me to communicate the following on chapter IX:2

As a professional sheep-breeder, I have undertaken the hybridization of Serinus hortulanus (serin) and Dryospiza canaria (canary), chiefly for the purpose of clarifying the laws of heredity.3 As a result I have encountered the laws of “Prosper Lucas” as reported by you.4 Exceptions to this occur only in the case of extreme individual potency, which in my experience is especially characteristic of strong animals.

Avoiding as much as possible all in-breeding, which as a breeder I must deplore, I have now crossed in the past year:

I: male 3132 Dryospiza 132 Serinus
female 1516 ditto 116 ditto
II: male 1516 Dryospiza 116 Serinus
female 78 ditto 18 ditto
III male 3132 Dryospiza 132 Serinus
female 3132 ditto 132 ditto
IV. male 78 ditto 18 ditto
female 3132 ditto 132 ditto

From all these matches offspring were produced and raised to adulthood.

I herewith provide for your inspection hybrid “parents” from both sides in

I with 6164 Dryospiza 364 Serinus
II " 2932 ditto 332 ditto
III " 3132 ditto 132 ditto
IV " 5964 ditto 564 ditto.

In order to get the same result in all circumstances as that already achieved, to form a new species, I carried on at the same time with hybridisation by “mating” different breeds, and I can provide the image of 6364 Dryospiza w. 164 Serinus, whose father is a hybrid (132 Serinus) & whose mother is Dryospiza.

I am happy to communicate further details at your request, and I authorise you to use this communication any way you like. The facts themselves I am ready to swear to at any time.

With the greatest respects | your most devoted | Rud. Riemann | Breslau, Centralbahnhof 31.

Currently at my | estate: | Zell am See, | duchy of Salzburg. | 9. VII. 75.

1
For a transcription of this letter in its original German, and a contemporary translation, see pp. 259–62.
2
Chapter 9 of Origin 6th ed. was on hybridism.
3
Riemann bred sheep on his estate at Sagschütz near Breslau (now Wrocław in Poland; for more on his theories of sheep breeding, see Riemann 1875). Serinus hortulanus is a synonym of Serinus serinus (the serin). Dryospiza canaria is a synonym of Serinus canaria (the wild canary). Crosses between canaries and finches are briefly mentioned in Origin 6th ed., p. 240.
4
Prosper Lucas is cited in Origin 6th ed., p. 261, on the ‘laws of resemblance’, namely, that offspring tend to resemble both parents even when the parents are of different varieties or species; and that cases in which the offspring more closely resemble one parent are rare in hybrids. CD’s extensively annotated copy of Lucas’s work on heredity (Lucas 1847–50) is in the Darwin Library–CUL (see Marginalia 1: 513–23).

Please cite as “DCP-LETT-10054,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-10054