54 BRITISH INSECTS 



secretion of which each member of the colony bears a 

 part. Other species of the family are the brown 

 scale, 1 and the cottony cushion scale, 2 both found on 

 currant bushes, also the " mealy-bugs." 3 



For the sake of continuity, the loathsome creatures 

 termed " lice " must be mentioned here. They con- 

 stitute the tenth order of insects the Anoplura and 

 are regarded by most authorities as degenerate allies 

 of the Heteroptera ; but their degradation due, 

 apparently, to long-continued parasitism is so great 

 that all obvious signs of relationship are obliterated. 

 They may be defined as small, wingless insects, which 

 spend their whole lives upon the bodies of mammals, 

 whose blood they suck. 



1 Lccanium. 2 Pulvinaria. 3 Dactylopius. 



