ON COLOUK 123 



and the longer period spent in hardening and 

 drying of the overlapping parts would favour 

 the development of dark pigment and of hairs. 

 Many species have the extreme apices of the 

 segments pale, but with the apical integument 

 so very thin, often looking nearly transparent 

 and membranous, that its development would be 

 very rapid. Again, in the case of red coloration, 

 the red generally occurs on the discs of the seg- 

 ments, the apices and sides often being dark, 

 and in cases where in one species both black and 

 banded forms occur, with intermediate varie- 

 ties, the last remnant of red colour is generally 

 situated in the centre of the segment. By far 

 the gayest effect is displayed by our humble 

 bees, and, but for them and a few of the species 

 of Andrena and the wasp-coloured species, our 

 aculeates would be a very sombre lot. 



