From Lawson Tait 12 March [1875]1
7, Great Charles St. | Birmingham.
Mar 12
Dear Sir,
I have had previous occasion to correspond with you on subjects bearing on evolution, and there is one more little matter on which I should like your opinion.2 As one of your disciples it has been my object to try the doctrine of evolution by survival of fitness at every possible point and amongst other things I have speculated on the origin of tails
For every tail I got a satisfactory reason, save for the bushy tail of such animals as the civet cat,3 some dogs, wolf &c. That variety long puzzled me until the accidental observation of a favourite white cat, who is perfectly deaf, solved the riddle to me On him I can perform experiments by reason of his deafness, without arousing his suspicion and I find that he uses his tail as a respirator to keep up his temperature. I catch him asleep before a German stove, lying at full length on his side with tail & limbs stretched out to enjoy the full heat. Then I intercept the heat by a screen & without waking he gradually coils himself up so as to cover as much surface as possible to save loss of heat. Then when I drive a current of cold air on him from a pair of bellows he twines his tail round him & buries his nose completely in the fur between it & the thigh, thereby establishing a natural respirator which must conserve his temperature to a very marked extent
Birds do the same thing when they bury their noses in their wings. I cannot find a bushy tailed animal which cannot curl itself up. If I could my theory would be spoilt
I mentioned this to my friend Prof Haughton4 of Dublin a few days ago when on a visit to him, and on a very cold morning we started round the Zoological Gardens to examine for the point. We found the civet cat & others coiled up & their noses covered with the fur. I do not know whether the observation is an original one or not, but it is at any rate interesting I purpose communicating a short note on it to the Birmingham Natural History Society and previous to that I should like to know your opinion of my theory.5
Yours faithfully | Lawson Tait
CD annotations
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Summary
Purpose of bushy tails; their usefulness to their owners as a means of keeping warm.
Letter details
- Letter no.
- DCP-LETT-9885
- From
- Robert Lawson (Lawson) Tait
- To
- Charles Robert Darwin
- Sent from
- Birmingham
- Source of text
- DAR 178: 2
- Physical description
- ALS 6pp
Please cite as
Darwin Correspondence Project, “Letter no. 9885,” accessed on 21 May 2024, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-9885.xml
Also published in The Correspondence of Charles Darwin, vol. 23