fission of, [64]; encystment of, [117].

Insects, duration of life amongst, [15];

duration of larval life of, [15];

normal death of, [22];

duration of imaginal life of, [38];

segmentation of egg of, [73];

deposition of eggs, [93];

origin of germ-cells of, [202];

polar bodies of, [218].

Instinct, [83];