ii6 



FRIDAY, 2 P.M. 

 GENERAL MEETING. 



President : E. B. Poulton. 

 Vice-President: H. J. Kolbe. 

 Secretary : M. Burr. 



To the great satisfaction of his many friends, Dr. Malcolm 

 Burr was present, and able to take his place as Secretary. 



The President called on Dr. Adalbert Seitz to give his 

 paper entitled : 



On the Sense of Vision in Insects. 



Description of experiments with paper models of butterflies. 

 Anthocharis charlo nia saw and recognised models of its own female 

 from a distance of eight feet. Models of other butterflies were 

 not attractive. Differences in size were appreciated. The sense 

 of smell was not in this case operative. Models turned round 

 so as to face in another direction showed that the males could 

 recognise orientation. Efforts to pair with paper models showed 

 that the males were not assisted by the sense of touch, a con- 

 clusion supported by the fact that when the wind caused the 

 paper-wings to flutter against them, they became more insistent. 

 Butterflies not disturbed by movement of natural objects such 

 as leaves and grass, but alarmed at approach of net, etc., showing 

 that they can recognise form. Experiences showing that butterflies 

 [Catopsilia philea) were able to recognise red from a greater dis- 

 ance than blue. Insects apparently unable to distinguish absence 

 of ultra-violet rays. Very little known concerning the physio- 

 logy of vertebrate vision. 



The President thanked Dr. Seitz for his interesting paper, 

 and called on Prof. Kellogg for his paper : 



