lO rnoCEEDINGS OF THE 



Dr. Harold Wager, F.K.S., 1\L.S., then delivered a lecture, 

 entitled, " On the Colour-sense of Wasps." He stated tliat the 

 experiments described in his paper were made by observing the 

 number of wasps flying towards, and settling upon, pieces of sugar 

 placed upon sheets of coloured paper arranged in various ways. 



The results of the experiments show that in seeking tiieir food 

 wasps (F<g67)« vtil(j((7'is) iive guided by tlieir social instinct, their 

 remembrance of locality, and their power to distinguish con- 

 spicuous colours or colour-contrasts. Tliey are probably also 

 guided by smell, but no experiments were made to test this. 



Under the conditions of the experiments wasps were attracted 

 by the strong colour-contrasts of white sugar on yellow, red, or 

 black paper, and less strongly by the weaker colour-contrasts of 

 white sugar on blue or white paper. They showed very little 

 discrimination among the various colours, but, so far as could be 

 judged, when they had a more or less free choice, untrammelled 

 by their stronger instincts, they flew to the colours in the follow- 

 ing order: yellow, black, red, blue, white. 



The wasps in the experiments showed a very pronounced 

 tendency to come back always to the exact place wiiere they had 

 previously obtained su<!:ar, irrespective of any colour that might 

 happen to be there. When the sugar was removed only a sliort 

 distance away they were much puzzled, and only after flying 

 about for some time were they able to discover it in its new place. 



Their social instincts were clearly indicated by the fact that 

 they were alw.fys more strongly attracted by other wasps than by 

 place or colour. This attraction for other wasps was so strong 

 that they would frequently fly at first to a piece of sugar sur- 

 rounded by dead wasps in preference to other pieces of sugar in 

 the immediate neighbourhood uhich were free of wasps. How- 

 ever, they very rarely settled on a piece of sugar surrounded by 

 dead wasps. 



Leaving out of account the probability that smell plays an im- 

 portant part in their activities, these experiments indicate that 

 the governing principles which dominate wasps in their search 

 for f(?od are, in the first place, the attraction exerted by the 

 presence of other wasps ; secondly, the tendency always to return 

 to the same place ; and, thirdly, the attraction due to conspicuous 

 colours and colour-contrasts. 



The lecture was illustrated by drawings on the blackboard and 

 some lantern-slides. 



Dr. Hahry Elthingham, F.Z.S, (visitor), gave an account of 

 his experiments on the colour-sense of Lepidoptera, with several 

 coloured lantern-slides ; Sir Henry Howorth, F.E.S. (visitor), and 

 Dr. G. B. Longstaff continued the discussion, the latter giving 

 instances from the behaviour of butterflies in the Tropics. 



Dr. AVager excused himself from replying on accouut of the 

 lateness of the hour. 



The paper by Mr. F. Lewis was postponed. 



