1870.] Mi\ Grant Allen on the Colour-Sense in Insects. 201 



WEEKLY EVENING MEETING, 



Friday, May 30, 1879. 



George Busk, Esq. F.R.S. Treasurer and Vice-President, 

 in tlio Chair. 



Grant Allen, Esq. 



The Colour-Sense in Insects : its Development and Beaction* 



The lecturer began by pointing out the probable absence of all bright- 

 coloured flowers and insects in the world whose fauna and flora have 

 been preserved to us by the primary rocks. Hence it might be 

 inferred that no animals then possessed a colour-sense, because there 

 were few or no coloured objects upon which it could be exercised. 



He traced the development of colour-perception in insects to the 

 gradual growth of entomophilous flowers. All parts of plants in 

 which oxidation is taking place are liable to display brilliant pig- 

 ments other than green ; and this is especially the case in the neigh- 

 bourhood of the floral organs. Flowers which exhibited this tendency 

 in a high degree would attract the eyes of insects, and so gain easier 

 fertilization. While, conversely, insects which were able to dis- 

 criminate such patches of colour to the greatest extent, would best 

 discover the pollen and honey. Thus nascent colour in flowers and 

 the nascent colour-sense in insects would develope side by side, till 

 they reached their present high point of perfection. 



But not only would a power to discriminate different hues arise 

 in the process of evolution : a taste for bright tints would also spring 

 up in the insect consciousness. This taste exerts itself actively in 

 the preference for beautiful mates, which is especially visible amongst 

 flower-haunting insects. The lepidoptera exhibit the brightest hues 

 of all, while the rose-chafers, the anthophilous diptera, and the other 

 tribes of like habit, rank next to them in beauty of colouration. 



The lecturer combated the idea that such selective preference 

 transcends the faculties of insects, and showed that various other facts 

 lead up to a similar conclusion. Certain species and genera were 

 proved by Miiller's observations to possess greater {esthetic sensibility 



* See the Lecturer's work ' The Colour-Sense : its Origin and Development. 

 An Essay in Comparative Psychology.' Triibner & Co. 1879. 



Vol. IX. (No. 71.) p 



