Encystment, relation to death of, [112], [115], [116], [120], [158];

protective, [117], [121];

of Rhizopoda, [121].

Entoniscidae, unequal length of life in male and female, [58].

Ephemeridae, length of life of imago of, [40], [156].

Epigenesis, theory of, [316].

Eristalis tenax, length of life of, [43].

Estheridae, [228].

Euglypha, identity of products of fission of, [26], [64], [65].

Eupithecia, length of life of, [45].