Ilyogenia, [388]

Imogine, [19]

Inarticulata, [517], [518]

Incudate, [210], [211]

Incus, in Rotifers, [210]

Inermia, [445]

Infusoriform embryos, [93]

Insects, parasites of, [142], [150], [152], [153], [154], [160], [163], [179], [183], [184], [185]

Internal sac, [509], [511]

Internode, [525]