Scale (insect anatomy) and enable the insect to escape. (Forsyth 1992:12) Thomas Eisner tested spiderwebs' effectiveness by dropping various insects onto the webs. Moths were consistently able to escape, and all left impact spots where scales had stuck to the web. Eisner found these spots to be common. (Eisner 2003:218-220) Scales also help increase the lift to drag ratio in gliding flight. Successive close-ups of the scales of a Peacock wing Scale (insect anatomy) The presence of scales on the wings of Lepidoptera, comprising moths and butterflies, characterises this order of insects. The name is derived from Ancient Greek λεπίδος (scale) and πτερόν
Comma category difference between the two notions is that a natural transformation is a particular collection of morphisms of type of the form formula_182, while objects of the comma category contains "all" morphisms of type of such form. A functor to the comma category selects that particular collection of morphisms. This is described succinctly by an observation by Huq that a natural transformation formula_183, with formula_184, corresponds to a functor formula_185 which maps each object formula_8 to formula_187 and maps each morphism formula_188 to formula_16. This is a bijective correspondence between natural transformations formula_181 and functors formula_185 which are sections of both