676 BEroET — 1881. 



TUE,SDAY, SEPTEMBER 6. 



The following Papers and Eeports were read : — 



1. On the Sense of Colour among some of the Lower Animals. 

 Bij Sir John Lubbock, Bart., M.P., F.B.S. 



The author began hy recording some elaborate experiments made on a species of 

 Daphnia, a small freshwater crustacean, with the spectrum. The general result 

 was that, in opposition to the opinion of M. Paul Bert, while their limits of vision at 

 the red end are approximately the same as ours, at the violet end they perceive 

 light which produces no impression on our eyes. 



He then proceeded to explain some experhnents he had made with bees, in order 

 to determine whether, and if so how, they are affected by different colours. 



The consideration of the causes which have led to the structure and colouring 

 of flowers is, he said, one of the most fascinating parts of natural history. Most 

 botanists are now agreed that insects, especially bees, have played a very important 

 part in the development of flowers. 



While in many plants, almost invariably with inconspicuous blossoms, the pollen 

 is carried from flower to flower by the wind, in the case of almost all large and 

 brightly coloured flowers this is effected by the agency of insects. In such flowers 

 the colours, scent, and honey serve to attract insects, while the size and form are 

 arranged in such a manner that the insects fertilise them with pollen brought from 

 another plant. 



Nevertheless these views have not escaped criticism. M. Bonnier, for instance, 

 has attempted to show that they are in many respects untenable. 



The author does not propose on the present occasion to follow his general argu- 

 ment, but merely that portion of it relating to colour. 



In order to test whether and how bees are afi'ected by different colours, he tried 

 the following experiment. He took slips of glass of the size generally used for slides 

 for the microscope, viz. 3 inches by 1, and pasted on them .slips of paper colom-ed 

 respectively blue, green, orange, red, white, and yellow. He then put them on a 

 lawn in a row about a foot apart, and on each put a second slip of glass with a 

 drop of honey. He also put with them a slip of plain glass with a similar drop of 

 honey. He had previously trained a bee to come to the spot for honey. His plan 

 then was, when the bee returned and had sipped about a quarter of a minute, to 

 remove the honey, when she flew to another slip. This then he took away, when 

 she went to a third, and so on. In this way he induced her to visit all the drops of 

 honey successively. "\Mien she had returned to the nest, he transposed all the upper 

 glasses with the honey, and also moved the coloured glasses. Thus, as the drop of 

 honey was changed each time and also the position of the glasses, neither of these 

 coidd influence the selection by the bee. 



In recording the results he marked down successively the order in which the bee 

 went to the different coloured glasses. For instance, in the first journey from the 

 nest, the bee lit first on the blue, which accordingly he marked 1 ; when disturbed 

 from the blue, she flew about a little and then lit on the white ; when the white 

 was removed, she settled on the green ; and so successively on the orange, yellow, 

 plain, and red. He repeated the experiment 100 times ; using two different hives, 

 and spreading the observations over some time, so as to experiment with diflerent 

 bees, and under varied circumstances. 



The precautions taken seem to him to have placed the different colours on an 

 equal footing ; while the number of experiments appears sufficient to give a fair 

 average. 



He may observe also that the different series agree well among themselves. 

 The difference between the numbers is certainly striking. Adding together 1, 2, 3, 

 4, 5, 6, and 7 we get 28 as the total number given bj^ each journey : 100 journeys, 

 therefore, give, as the tablp shows, a total of 2,800, which divided by 7, would of 

 course, if no preference were shown, give 400 for each colom-. The numbers, how- 



