OF WASHINGTON. 141 



As regards Mimicry, Col. Swinhoe's recent work upon a 

 group of butterflies related to Hypolimnas bolina was shown by 

 illustrations. These butterflies, when traced over the whole of 

 their range as far as it is at present known, were found to mimic 

 the local and unpalatable Eupkea, or in the case of Celebes and 

 Africa, the local Danais. In Africa both males and females are 

 invariably mimetic. On the other hand, in Asia and the Malay 

 Archipelago, as a rule, the females only are mimetic. The 

 closely-related Hypolimnas misippus always accompanies Da 

 nais chrysippus, and its female invariably mimics this butterfly. 



Another series of illustrations proved that the loss of scales by 

 transparent-winged Lepidoptera during their first flight is due to 

 the rudimentary form of the stalk by which the scale is attached 

 and of the socket into which it fits. In the case of one moth 

 which was a more perfect mimic of a hymenopterous insect 

 than another, the scales which fall off are more rudimentary, and 

 support the view that the more perfect mimic has passed through 

 a longer history of change than the less perfect one, thus allow 

 ing the useless scales to become more degenerate. 



Illustrations of the larval form of a Membracid insect which 

 mimics the leaf-carrying ants of tropical America were then 

 brought forward, and it was seen that the leaf is represented by 

 the flattened dorsal part of the body of the Homopteron. 



Finally a series of illustrations was given, showing the loss of 

 decorative coloring in the males of certain day-flying moths as 

 the females become progressively degenerate the degeneracy of 

 one sex and loss of color in the other reaching their climax in 

 the genus Psyche. 



Upon the conclusion of the address, which was warmly ap 

 plauded, Mr. Fernow congratulated the Society upon the oppor 

 tunity which it had had of listening to what was probably the 

 broadest and most interesting paper which had been presented 

 before it since its organization. He moved a hearty vote of 

 thanks to the lecturer. The motion was seconded by Mr. How 

 ard, and carried unanimously. The hour for adjournment had 

 nearly arrived upon the completion of the lecture, and there was 

 no time for specific discussion, but brief remarks of a general 

 character were made by Prof. Ward, Dr. Dall, Mr. Fernow, 

 and Prof, Poulton, 



