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Darwin Correspondence Project

From Eduard Schulte1   23 October 1879

Fürstenwalde | Prov. Brandenburg.


Carolo Darwin | Viro Ornatissimo et Doctissimo | S. P. D˘.2 | Eduardus Schulte philosophiae doctor.

Mittebam tibi, Vir Ornatissime, imaginem et descriptionem papilionis cujusdam, qui in insula Celebe3 reperitur et colorum varietate, quam nuper inveneram et accuratius investigaveram, notabilis et insignis est. Putabam, hanc descriptionem tibi gratam fore, si quidem eum papilionem nondum noveras, nam ut hanc varietatem cognosceres, credebam tua non parvi interesse ad vim rationemque differentiae generum apud papiliones indagandum.


[Enclosure 1]


Hypolimnas sive Diadema Bolina,4 mas.

Ex insula Celebe.

(Ad naturae mensuram descriptus.)

Alae (γ) sunt nigrae.

Oculi (β) sunt albi.

Anuli (α) sunt modo nigri, modo caerulei.

Lineis atramento factis via fulgoris caerulei indicatur.

A, B, C˘, D˘ sunt loci spectantium.

[Enclosure 2]

Inter marem et feminam hujus papilionis pernimium interest, nam quamquam pars inferior utriusque nihil differt vel haud multum, partes superiores coloribus valde inter se distinguuntur. Alae maris (γ) sunt nigrae, loci sive oculi β sunt albi. Anuli α, qui spectantium oculos in se maxime convertunt, modo nigri sunt, ut alae, modo caerulei, ut caelum. Quum lumen ex loco B adit, is, qui in loco D˘ est, colorem caeruleum non videt, neque quum lumen ex loco A adit, is, qui in loco C est, colorem caeruleum videt. Quem ut videas, necesse est, lumen aut a tergo aut a parte sive dextra sive sinistra spectantis penetrare. Ex conditione, ut lumen apte et commode adeat, ex loco B vides anulos α III et IV caeruleo splendore mirum in modum micantes, ex loco D˘ anulos I et II, ex loco A anulos II et IV. Nunquam vides quatuor anulos eodem tempore simul micantes, neque unquam modo tres anulos. Nam quum ex angulo B C papilionem conspicis, solus anulus III plene et perfecte sibi micat, ex anulis I et IV autem nihil nisi particula quaedum splendorem illum parebet. Itaque numquam plus quam duo anuli simul micant, ut aut unus anulus et alter luceat aut unus et dimidia pars alterius et dimidia pars tertii. Qui a tergo papilionis (C˘) spectat, caeruleum fulgorem nisi ex minimis partibus anuli I (Ii) et III (IIIi) omnino non videt, ac merito quidem, nam maris nihil interest, ab hac parte spectari, quo oculi ejus non penetrant: vult enim feminae animum colorum varietate delenire et admiratione rei novae defigere, et ipse id agit, ut admirantem feminam animadvertat et stupore defixam opprimat voluptateque permulceat. Mirum profecto est, quod natura actionem levandi demittendique alas, quae papilionum mares feminas alliciunt, aliis papilionibis utilem, huic quodammodo necessariam esse voluit: sive hac actione enim splendor ille magnificentissimus vel omnino non spectaretur vel non satis: ita hujus papilionis et splendor et actio alarum et ars amandi magis conjuncta sunt quam in alio papilione.

[Enclosure 3]

He who looks at the butterfly from behind does not see the brilliant blue except from a very small part of the rings on the front wings, and there is reason in this for it is of no interest to the male to be looked at from this side where his eyes do not penetrate (This seems utter bosh)5 for he wishes to charm the female by the variety of his colours, and he acts in such a way that he may attract the attention of the female and obtain her admiration. It is a wonderful thing that nature has decreed that the action of raising and lowering the wings (by which male butterflies attract the females)—useful in other butterflies should be in a certain sense necessary to this one. For without this action this most magnificent splendour would be either not at all or not enough admired.


For a translation of this letter, see Appendix I.
SPD: salutem plurimam dicit (Latin), ‘bids the best possible health’, or, ‘greets’.
Celebes (now Sulawesi) is an island in Indonesia.
Hypolimnas bolina is the common eggfly. CD referred to the butterfly under the synonym Diadema bolina in Descent 1: 413.
The contemporary partial translation is in the hand of Francis Darwin; he added this comment in pencil.


From Eduard Schulte1   23 October 1879

Fürstenwalde | Prov. Brandenburg.


Eduard Schulte, doctor of philosophy, to the very distinguished and learned Charles Darwin, greetings.

I am sending to you, most honoured Sir, an illustration and description of a certain butterfly that is found on the island of Celebes2 and is extraordinarily significant because of its colour variation, which I have recently discovered and have investigated in detail. I think that you will welcome this description, if indeed this butterfly is not already known to you; for I believe that knowledge of this variation will be of no small value to you in your hunt amongst butterflies for the significance and explanation of diversity.


[Enclosure 1]


Hypolimnas or Diadema Bolina,3 male.

From the island of Celebes

(Drawn life size.)

Wings (γ) are black.

Eyes (β) are white.

Rings (α) are sometimes black, sometimes blue.

The direction of the blue flash is shown by lines drawn in ink.

A, B, C˘, D˘ are viewing positions.

[Enclosure 2]

There is a considerable difference between the male and female forms of this butterfly, for while the under part of each does not differ at all or not very much, the upper parts are strongly distinguished by their colours. The wings of the male (γ) are black, the spots or eyes β are white. The rings α, which particularly draw the eye of the viewer, are sometimes black, like the wings, and sometimes blue, like the sky. When light comes from point B, someone who is at point D does not see the blue colour, and when the light comes from point A, someone who is at point C does not see the blue colour. In order for you to see the colour, the light must enter from the back or from the right or left side of the viewer. When it happens that the light shines properly at the right moment, from point B you see rings α 3 and 4 flashing in an amazing way with brilliant blue; from point D˘ rings 1 and 2, from point A rings 2 and 4. You never see four rings flashing together at the same time, and never even three rings. For when you view the butterfly from angle B C, only ring 3 flashes completely in its entirety, and nothing but a certain small section from rings 1 and 4 produces that brilliance. Thus never more than two rings flash at the same time, so that either one ring and a second shines, or one ring and a half of a second and a half of a third. Someone who looks from behind the butterfly (C˘) does not see the blue flash at all except from the smallest parts of rings 1 (1i) and 3 (3i), and indeed that is as it should be, because it is not in the male’s interest to be viewed from a direction where his vision does not reach: for he wishes, by means of the colour variation, to catch the attention of the female and astound her with admiration of the novelty, and he himself does this to attract the admiring female and overwhelm her, motionless with wonder, and delight her with desire. Really it is amazing that nature has decreed that the action of raising and lowering the wings, by which the male butterflies attract the females, useful to other butterflies, is in a way vital to this one: for if it did not do this, then that most magnificent splendour would either not been seen at all or not enough: thus in this butterfly its splendour, the action of its wings, and the art of love are more closely joined together than in any other butterfly.


For a transcription of this letter in its original Latin, and a partial contemporary translation, see Transcript.
Celebes (now Sulawesi) is an island in Indonesia.
Hypolimnas bolina is the common eggfly. CD referred to the butterfly under the synonym Diadema bolina in Descent 1: 413.


Sends drawing and description of butterfly discovered in Celebes. It is noteworthy for its colour, which plays a role in mating.

Letter details

Letter no.
Eduard Schulte
Charles Robert Darwin
Sent from
Source of text
DAR 177: 64
Physical description
ALS 3pp (Latin), sketch, trans 2pp

Please cite as

Darwin Correspondence Project, “Letter no. 12254,” accessed on 15 April 2024,