EYE-SPOTS ON BUTTEKFLIES* WINGS: 1868 233 



me, and for your two pieces of information in your note 

 about the sexes of the Batchian Butterfly and about the 

 Longicorn Beetle. 1 



With many thanks, pray believe me 



Yours very sincerely 



CH. DARWIN 



10. 



Jan. 16th[, 1868.] DOWN. 



BROMLEY. 



KENT. S.E. 

 MY DEAR MR TRIMEN 



I really do not know how to thank you enough for 

 all the great trouble which you have taken for me. 

 I never saw anything so beautiful as your drawings. 2 

 I have examined them with the microscope ! ! When 

 I asked for a sketch I never dreamed of your taking 

 so great trouble. Your letter and Proof-sheet give me 

 exactly and fully the information which I wanted. I am 

 very glad of the description of the ocellus in the 

 S. African Saturnidce : 3 I had no idea it was so com- 



1 In The Descent of Man (1874), 250, Darwin quotes A. R. 

 Wallace's observation, doubtless supplied to him by Trimen, and 

 here referred to, that the female of Omithoptera ctvesus was 

 commoner and more easily caught than the male. Mr. Trimen 

 thinks that this must be the ' Batchian Butterfly '. On p. 294 

 n. 63 Darwin states that he had been informed by Trimen that 

 the male of a species of the Lamellicorn genus Trichius is more 

 obscurely coloured than the female. Trimen's name is not men- 

 tioned in connexion with the similar relationship recorded for 

 certain Longicorn beetles on pp. 294, 295. 



2 The drawings were illustrations of the extreme variation in the 

 development of the eye-spots on the wings of Cyllo (Melanitis) leda. 

 Darwin referred to these and figured some of them in Descent of 

 Man (1874), 428, 429. 



3 Darwin is here evidently alluding to the description given 

 him by Trimen of the 'S. African moth (Gynanisa isis), allied 

 to our Emperor moth, in which a magnificent ocellus occupies 

 nearly the whole surface of each hinder wing'. Descent of Man 

 (1874), 428. 



