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 by Lawvere, which involved the comma punctuation mark. Although standard notation has changed, since the use of a comma as an operator is potentially confusing, and even Lawvere dislikes the uninformative term "comma category" (Lawvere, 1963 p. 13), the name persists. The most general comma category construction involves two functors with the same codomain. Often one of these will have domain 1 (the one-object one-morphism category). Some accounts of category theory consider only these special cases, but the term comma category is actually much more general. Suppose that formula_1, formula_2, and formula_3 are categories, and formula_4 and formula_5 (for source