26 Transactions. — Miscellaneous. 



of vision possessed by the European insect. I afterwards 

 proved this by experiment. When a number of both insects 

 were resting close together I would gradually move my hand 

 towards them, and I noticed that the introduced blowflies 

 invariably saw my hand and took wing before the native 

 species. I verified this by numerous experiments and always 

 obtained the same results. 



Ordinary observation in the field proves that some insects 

 undoubtedly have very keen sight, and almost every one must 

 have noticed that dragon-flies and butterflies are especially 

 well endowed in this respect. 



Another interesting question in connection with the vision 

 of insects is the relative functions of the simple and com- 

 pound eyes. A large number of experiments have been made, 

 and it appears probable that the ocelli are useful in dark 

 places and for near vision. Lord Avebury adds : " Whatever 

 the special function of the ocelli may be, it seems clear that 

 they must see in the same manner as our eyes do — that is to 

 say, the image must be reversed. On the other hand, in the 

 case of the compound eyes it seems probable that the vision 

 is direct, and the difficulty of accounting for the existence in 

 the same animal of two such different kinds of eyes is certainly 

 enhanced by the fact that, as it would seem, the image given 

 by the medial eyes is reversed, while that of the lateral ones 

 is direct." 



The modern theories of the evolution of flowers through 

 the agency of insect visitors is now very generally accepted 

 amongst naturalists, but it is obvious that these ideas would 

 be effectually disproved if it could be demonstrated that 

 insects were unable to distinguish colours. The following 

 experiments conducted by Lord Avebury prove, I think, 

 that bees, at any rate, possess the faculty of distinguishing 

 colours : " I brought a bee to some honey which I placed 

 on a slip of glass laid on blue paper, and about 3 ft. off I 

 placed a similar drop of honey on orange paper. With a 

 drop of honey before her a bee takes two or three minutes 

 to fill herself, then flies away, stores up the honey, and 

 returns for more. My hives were about 200 yards from the 

 window, and the bees were absent about three minutes, or 

 even less. When working quietly they fly very quickly, and 

 the actual journeys to and fro did not take more than a few 

 seconds. After the bee had returned twice I transposed the 

 papers ; but she returned to the honey on the blue paper. I 

 allowed her to continue this for some time, and then again 

 transposed the papers. She returned to the old spot and 

 was just going to alight when she observed the change of 

 colour, pulled herself up, and without a moment's hesitation 

 darted off to the blue. No one who saw her at that moment 



