172 



The Irish Naturalist. 



September, 



skill between pink-flowered and yellow -flowered plants of exactly the 

 same species ? The latter feat would be the true proof of colour discri- 

 mination ; and it was this sort of discrimination that struck me as so 

 remarkable in the Hive -Bee when I watched its operations at the wall- 

 flower-bed as detailed in my paper on " Bees and Flowers." The wall- 

 flowers were all of one species, differing from one another in nothing but 

 colour, and even the colour -differences were not by any means so marked 

 as that between pink and yellow ; yet each bee confined itself to one of 

 the three colour-varieties represented — plain brown, plain yellow, or brown 

 and yellow streaked. 



I have not yet got conclusive proof that any species of Bombus will 

 regard distinctions of colour where no other difference presents itself in 

 the flowers the bee is visiting. I have seen B. agrorum, when working at 

 Milkwort, transfer its attention with seeming indifference from pink to 

 blue and from blue to pink — showing, on the one hand, that it had enough 

 botanical acumen to recognise the specific identity of these flowers in spite 

 of a conspicuous difference in their colours, and, on the other hand, that 

 the difference in colour did not seem to this bee a matter of practical 

 importance. Its action might almost have suggested doubts as to whether 

 it saw the colour difference at all ; but as I once saw a bee of the same 

 species visit 24 flowering spikes of blue milkwort in succession, neglecting 

 pink, I cannot suppose that the colour sense is absent, though its teachings 

 are so often disregarded. 



This summer I have been particularly interested in watching another 

 of the yellow bees, Bombus distinguendus , at a spot much frequented by 

 it, where it busied itself during July in collecting honey from bramble - 

 blossoms. Two forms of bramble, plainly though perhaps only sub- 

 specifically distinct, abound in this patch of ground, and are closely inter - 

 minged. I will hazard no guess at their names, but one has large showy 

 blossoms of a rosy pink hue, while the petals of the other are small, narrow, 

 and of a very dull or almost greenish white. With strange perversity, 

 Bombus distinguendus sticks to the dull whitish flowers and leaves the 

 bright pink ones alone. I can almost imagine the indignation of a 

 " lumping" botanist at the idea of a bumble-bee discriminating in this 

 way between two forms of the " Common Blackberry." I suppose the 

 only explanation he could suggest would be that Bombus distinguendus 

 has some preference for white over pink as a colour. But for my part I 

 do not think the bee distinguishes these plants by their colour at all ! At 

 any rate, I have several times seen an individual bee dart straight to one 

 of the big pink blossoms as though to gather from it, but when almost in 

 contact with the flower it would discover it had made a mistake and dart 

 away again. Surely, if it saw the flower a foot away, it did not need to 

 come within half an inch before discovering that it was pink, not white. 

 It must either have seen that fact at the first, or not have minded it at the 

 last stage. I can only conclude that some other difference than that of 

 colour determines the discrimination shown by this species of Bombus — at 

 any rate with regard to brambles. 



C. B. Moffat. 



Ballyhyland, Co. Wexford. 



