1083. Why have many insects a great number of eyes?
Because the orb of the eye is fixed; there is therefore placed over the eye a multiple-lens, which conducts light to the eye from every direction; so that the insect can see with a fixed eye as readily as it could have done with a movable one. As many as fourteen hundred eyes, or inlets of light, have been counted in the head of a drone-bee. The spider has eight eyes, mounted upon different parts of the head; two in front, two in the top of the head, and two on each side.
1084. Why have birds of prey no gizzards?
Because their food does not require to be ground prior to digestion, as does the food of grain-eating birds.
1085. Why have earth worms no feet?
Because the undulatory motion of their muscles serves them for fill the purposes of progression needed by their mode of life.
1086. Why have mussels strong tendinous threads proceeding from their shells?
Because as they live in places that are beaten by the surf of the sea, they moor their shells by those threads to rocks and timbers.