ON COLOUR 121 



there is often a dense clothing of coloured hairs 

 sometimes so dense that the surface of the body 

 may be rendered invisible. These coloured hairs 

 may be distributed into brilliant bands, as in the 

 humble bees, or they may be uniformly black, 

 as in some of their varieties and in the females 

 of the spring species of Anthophora (pi. D, 25), 

 or entirely red as in Andrena fidva (pi. B, 16), 

 or black on the thorax and red on the abdomen 

 as in Osmia bicolor (pi. D, 28), or vice versa as in 

 Andrena thoracica, etc., but the most usual con- 

 dition is that where the hairs form more or less 

 pale bands along the joints of the segments, 

 either immediately above or below them or both ; 

 sometimes these bands are very obscurely indi- 

 cated, and visible only in certain positions. At 

 others they are vividly white ; to a certain extent 

 this banded condition recalls the waspy colora- 

 tion. The hairs, however, of the bands are rarely 

 yellow, but as a rule greyish or white, or of a 

 grade of colour slightly paler than those of the disc. 

 There are some rather interesting points which 

 arise out of this rough analysis. Among the bees, 

 all the species which have a waspy coloration 

 are cuckoos, with only one exception (Anthidium) 



