64 MAN [CHAP. VIII 



Letter 433 To J. Jenner Weir. 



Mr. John Jenner Weir, 1 to whom the following letters are addressed, 

 is frequently quoted in the Descent of Man as having supplied Mr. 

 Darwin with information on a variety of subjects. 



Down, Feb. 2;th [1868], 



I must thank you for your paper on apterous lepidoptera, 2 

 which has interested me exceedingly, and likewise for the 

 very honourable mention which you make of my name. It 

 is almost a pity that your paper was not published in some 

 Journal in which it would have had a wider distribution. It 

 contained much that was ne\v to me. I think the part about 

 the relation of the wings and spiracles and tracheae might have 

 been made a little clearer. Incidentally, you have done me 

 a good service by reminding me of the rudimentary spurs on 

 the legs of the partridge, for I am now writing on what I 

 have called sexual selection. I believe that I am not mistaken 

 in thinking that you have attended much to birds in confine- 

 ment, as well as to insects. If you could call to mind any 

 facts bearing on this subject, with birds, insects, or any animals 

 such as the selection by a female of any particular male 

 or conversely of a particular female by a male, or on the rivalry 

 between males, or on the allurement of the females by the 

 males, or any such facts, I should be most grateful for 

 the information, if you would have the kindness to com- 

 municate it. 



P.S. I may give as instance of [this] class of facts, that 

 Barrow asserts that a male Emberiza (?) at the Cape has im- 

 mensely long tail-feathers during the breeding season ; 3 and 

 that if these are cut off, he has no chance of getting a wife. I 

 have always felt an intense wish to make analogous trials, but 

 have never had an opportunity, and it is not likely that you or 

 anyone would be willing to try so troublesome an experiment 

 Colouring or staining the fine red breast of a bullfinch with 



1 For a biographical note see Vol. I., Letter 235. 



2 Published by the West Kent Natural History, Microscopical and 

 Photographic Society, Greenwich, 1867. Mr. Weir's paper seems chiefly 

 to have interested Mr. Darwin as affording a good case of gradation 

 in the degree of degradation of the wings in various species. 



3 Barrow describes the long tail feathers of Emberiza longicauda as 

 enduring "but the season of love." A?i Account of Travels into the 

 Interior of Southern Africa: London, 1801, Vol. I., p. 244. 



