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Darwin Correspondence Project

From J. J. Weir   27 June 1870

6 Haddo Villas | Blackheath, SE

27th June 1870

My Dear Sir

How I have longed, during my protracted illness, to reply to your enquiries, but this is the first day I have felt myself able, although still very weak & my nerves in a tremble.1

In some way or other, I poisoned my hand, the disease spread rapidly, assumed a malignant form, & necessitated a series of acutely painful surgical operations.—

The agony endured during ten days night & day was beyond anything I ever felt, but I will not trouble you further with my own complaints, & have only said this much by way of apology for the delay in answering your kind letter.—

I should say as a general rule that birds when frightened closely adpress their feathers & it is astonishing the apparent reduction in bulk, that fear appears to produce in most species, I have noticed it most in the Melopsittacus undulatus, & in the Quail, the latter when frightened looks about half the size when undisturbed. One of the first things a bird does when recovering from a surprise is to shake out the feathers.2 Some finches when angry, erect the feathers all over the body most species however only spread out the wings and tail, among the former, the Canary, Goldfinch & preeminently, the Goldfinch male, make each “dividual” feather “to stand on end like quills upon the fretful porcupine”.

I have a Goldfinch male, often in my dining room, of the most irascible disposition, even if a servant when waiting at table goes too near the cage, he at once appears a ball of erected feathers3

The irascibility of most birds, Robin4 excepted, is greatest during the breeding season, & many then which do not erect the feathers all over the body, erect a ruff of them round the neck, all the buntings & most of the finches do this, the Chaffinch5 at the same time shewing a small concealed crest at the back of the head, a spot in the same place is not concealed in the female, nor in either sex of the Brambling, “Fringilla montifringilla, nearly all when angry rush at each other with open beak & with threatening gestures.

As to birds exhibiting impatient gestures, the only birds I have observed in my aviary, which shew by signs they are hungry are the Siskins,6 these if hungry as soon as they see me cling to the wires of the aviary, it may be observed the species mostly seeks its food clinging like a Tit.—

There is one curious habit of captive Ratels7 which has much interested me, they are in the constant habit of turning summersaults, the head & back being brought with considerable force on to the ground, this appears to me to be the action, which these mellivorus mammals use, to free themselves from the bees, which must attack them in great numbers, when robbing their hives.—

I forgot to observe when speaking of the erection of feathers that the angry robin erects the feathers all over the body, the Whitethroat, C Cinerea,8 also erects them all around the throat.—

I shall be glad to give at all times any further information in my power.—

I take the opportunity now to mention a few other subjects—

The first bears on the Cytisus Adami.—

My Brother has but two kinds of Laburnum viz Cytisus purpureus, very erect, & Cytisus Alpinus? very pendulous, he had several stocks of the latter grafted with the purple one, & this year, the grafts being two years old, I saw in one, fairly above the stock, about four inches, a raceme of purely yellow flowers, with the usual dark markings, and above them a bunch of purely purple flowers, the branches of the graft in no way shewed an intermediate character, but had the usual rigid growth of Purpureus.—9 The second case bears on latent gemmules.—10

My Brother keeps a large number of Rabbits at Brenchley, not that he is a “Fancier’ of them, he has had the breed a long time & they are supposed to be pure bred English lop eared.—

Some time since, in a litter, there appeared one with the very thick coat which distinguishes the variety known as the French, the hair was remarkably long & woolly, but the peculiarity was that it was a grey a color Harrison had never seen in the French variety.—

The specimen was a male & he had from 30 to 40 young from it, without one shewing a trace of the long hair of the male parent, but curiously enough this Spring a litter appeared from a doe, not a descendant of the long hair, with 4 young of the long haired variety, and one of the usual smooth haired.—

The four young were all fawn in color.— The third case bears on the question of hereditary mutilations.—

You will recollect 〈two pages missing

the bones were put by for you, but unfortunately were mislaid & lost.—11

The fourth case bears on the question of contagious variegation in plants.—

I have an ivy called the Golden lobe, by Gardeners Hedera helix aurea densa, this has twined into a common Hedera helix12 which from its close habit I call the clinger; now the clinger has caught the yellow mottling from Aurea Densa, & thus a perfectly new variety has been formed, which was much needed as Aurea Densa was rather too arboreal in its growth.—

Had it been a mere sport I should not have attached any importance to it, but the improbability of the sport being like Aurea Densa, with which its roots & branches are so intimately intertwined, is very great unless by infection or rather perhaps contagion.

I enclose a leaf of Aurea Densa, lobed shaped, of the clinger before sporting & afterwards.—

I am surprised I have had strength to write so much, but I am so interested in your subjects & your enquiry was quite a solace during my illness.—

Believe me | Yours very sincerely | J Jenner Weir

C Darwin Esqr.

CD annotations

1.1 How … letter.— 3.3] crossed pencil
4.1 I should say] after opening square bracket pencil
4.4 One … feathers. 4.5] scored blue crayon
4.6 Some … tail, 4.7] underl blue crayon
6.2 erect … do this, 6.3] scored blue crayon
6.6 “Fringilla … gestures. 6.7] double scored red crayon
6.6 nearly … gestures. 6.7] scored blue crayon
7.1 As … hives.— 8.5] crossed pencil
8.1 There … hives.— 8.5] ‘Ratels’ pencil
10.1 I shall … Adami.— 12.1] crossed pencil
13.1 My Brother] after opening square brackets blue crayon, pencil
13.7 The second case] after opening square bracket red crayon
13.7 latent gemmules] closing square bracket blue crayon, del blue crayon
14.1 My Brother … eared.— 14.3] ‘Reversionadded pencil
14.1 My Brother] after opening square bracket red crayon
14.1 My Brother … variety.— 15.4] crossed pencil
21.1 I have … growth.— 21.5] ‘(Contagion of Variegation)’ pencil, square brackets in MS
21.1 I have] after opening square bracket pencil
24.1 I am … illness.— 24.2] crossed pencil
Top of letter: ‘J. Jenner Weir | Expression) | (Erection of feathers)’ pencil


For CD’s enquiries, see the letter to J. J. Weir, 14 June [1870].
CD cited Weir for this information in Expression, p. 100. Melopsittacus undulatus is the budgerigar. The quail is Coturnix coturnix.
CD cited Weir for the information about angry birds fluffing out their feathers in Expression, p. 99. Weir quotes from Shakespeare’s Hamlet 1: 5. The canary is Serinus canaria; the goldfinch, known to CD as Carduelis elegans, is now C. carduelis.
Erithacus rubecula, the European robin.
Fringilla coelebs.
Carduelis spinus, the Eurasian siskin.
Mellivora capensis, also known as the honey badger.
Weir presumably refers to the European or common whitethroat, Sylvia communis, formerly Sylvia cinerea or Curruca cinerea (see Montagu 1831, p. 538).
Weir’s brother was Harrison William Weir. CD discussed Cytisus adami in Variation 1: 387–90 and 2: 364–5. Cytisus adami, a graft hybrid of the common yellow laburnum C. laburnum (now Laburnum anagyroides) and C. purpureus, a dwarf purple broom, is now known as +Laburnocytisus adamii (Bean 1970–88, 2: 510–11). See also Correspondence vol. 13, letter to J. D. Hooker, [1 May 1865] and n. 3.
Latent gemmules were a feature of CD’s hypothesis of pangenesis (see Variation 2: 357–404), according to which cells threw off minute granules (gemmules) that circulated freely throughout the system, and had the potential to develop into cells like those from which they were derived (ibid., p. 374).
CD evidently tore off the half-sheet describing this case, which has not been identified.
Hedera helix is the English ivy.


On behaviour of birds when frightened and when threatening.

Purple Cytisus grafted onto yellow stock produces some yellow flowers.

Mutations in rabbits.

Cites case of variegated leaf form of one plant apparently spreading to a neighbour.

Letter details

Letter no.
John Jenner Weir
Charles Robert Darwin
Sent from
Source of text
DAR 181: 82
Physical description
22pp inc †

Please cite as

Darwin Correspondence Project, “Letter no. 7247,” accessed on 28 July 2017,

Also published in The Correspondence of Charles Darwin, vol. 18