Letter icon
Letter 7247

Weir, J. J. to Darwin, C. R.

27 June 1870


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.


6 Haddo Villas | Blackheath, SE

27th June 1870

My Dear Sir

How I have longed, during my protracted illness, to reply to yourenquiries, but this is the first day I have felt myself able, althoughstill very weak & my nerves in a tremble.f1

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

The agony endured during ten days night & day was beyond anything Iever 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 answeringyour kind letter.—

I should say as a general rule that birds when frightened closelyadpress their feathers & it is astonishing the apparent reduction inbulk, that fear appears to produce in most species, I have noticed itmost in the Melopsittacus undulatus, & in the Quail, the latter whenfrightened looks about half the size when undisturbed. One of thefirst things a bird does when recovering from a surprise is to shakeout the feathers.f2 Some finches when angry, erect the feathers allover the body most species however only spread out the wings and tail,among the former, the Canary, Goldfinch & preeminently, the Goldfinchmale, make each “dividual” feather “to stand on end like quillsupon the fretful porcupine”.

I have a Goldfinch male, often in my dining room, of the most irascibledisposition, even if a servant when waiting at table goes too near thecage, he at once appears a ball of erected feathersf3

The irascibility of most birds, Robinf4 excepted, is greatestduring the breeding season, & many then which do not erect thefeathers all over the body, erect a ruff of them round the neck, allthe buntings & most of the finches do this, the Chaffinchf5 at thesame time shewing a small concealed crest at the back of the head, aspot in the same place is not concealed in the female, nor in eithersex of the Brambling, “Fringilla montifringilla, nearly all when angryrush at each other with open beak & with threatening gestures.

As to birds exhibiting impatient gestures, the only birds I have observedin my aviary, which shew by signs they are hungry are the Siskins,f6these 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 likea Tit.—

There is one curious habit of captive Ratelsf7 which has much interestedme, they are in the constant habit of turning summersaults, the head &back being brought with considerable force on to the ground, this appearsto me to be the action, which these mellivorus mammals use, to freethemselves 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 thatthe angry robin erects the feathers all over the body, the Whitethroat,C Cinerea,f8 also erects them all around the throat.—

I shall be glad to give at all times any further information inmy 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, veryerect, & Cytisus Alpinus? very pendulous, he had several stocksof the latter grafted with the purple one, & this year, the grafts being twoyears old, I saw in one, fairly above the stock, about four inches,a raceme of purely yellow flowers, with the usual dark markings, andabove them a bunch of purely purple flowers, the branches of thegraft in no way shewed an intermediate character, but had the usualrigid growth of Purpureus.—f9 The second case bears on latentgemmules.—f10

My Brother keeps a large number of Rabbits at Brenchley, notthat 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 thickcoat which distinguishes the variety known as the French, the hairwas remarkably long & woolly, but the peculiarity was that it was a greya color Harrison had never seen in the French variety.—

The specimen was a male & he had from 30 to 40 young from it, withoutone shewing a trace of the long hair of the male parent, but curiouslyenough this Spring a litter appeared from a doe, not a descendant ofthe long hair, with 4 young of the long haired variety, and one of theusual smooth haired.—

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

You will recollect ⟨two pages missing

the bones were put by for you, but unfortunatelywere mislaid & lost.—f11

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

I have an ivy called the Golden lobe, by Gardeners Hederahelix aurea densa, this has twined into a common Hedera helixf12 whichfrom its close habit I call the clinger; now the clinger has caughtthe yellow mottling from Aurea Densa, & thus a perfectly new varietyhas been formed, which was much needed as Aurea Densa was rather tooarboreal 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 whichits roots & branches are so intimately intertwined, is very greatunless by infection or rather perhaps contagion.

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

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

Believe me | Yours very sincerely | J Jenner Weir

C Darwin Esqr.

DAR 181: 82



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 isCoturnix coturnix.
CD cited Weir for the information about angry birds fluffing outtheir feathers in Expression, p. 99. Weir quotes from Shakespeare’sHamlet 1: 5. The canary is Serinus canaria; the goldfinch, knownto 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 (seeMontagu 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 laburnumC. laburnum (now Laburnum anagyroides) and C. purpureus, a dwarfpurple broom, is now known as +Laburnocytisus adamii (Bean 1970–88,2: 510–11). See also Correspondence vol. 13, letter toJ. 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 offminute granules (gemmules) that circulated freely throughout thesystem, and had the potential to develop into cells like those fromwhich they were derived (ibid., p. 374).
CD evidently tore off the half-sheet describing this case, whichhas not been identified.
Hedera helix is the English ivy.
Maximized viewPrint letter