ICHNEUMONIDÆ.—A family of hymenopterous insects, the members of which lay their eggs in the bodies or eggs of other insects.
IMAGO.—The perfect (generally winged) reproductive state of an insect.
INDIGENES.—The aboriginal animal or vegetable inhabitants of a country or region.
INFLORESCENCE.—The mode of arrangement of the flowers of plants.
INFUSORIA.—A class of microscopic animalcules, so called from their having originally been observed in infusions of vegetable matters. They consist of a gelatinous material enclosed in a delicate membrane, the whole or part of which is furnished with short vibrating hairs (called cilia), by means of which the animalcules swim through the water or convey the minute particles of their food to the orifice of the mouth.
INSECTIVOROUS.—Feeding on insects.
INVERTEBRATA, or INVERTEBRATE ANIMALS.—Those animals which do not possess a backbone or spinal column.
LACUNÆ.—Spaces left among the tissues in some of the lower animals and serving in place of vessels for the circulation of the fluids of the body.
LAMELLATED.—Furnished with lamellæ or little plates.
LARVA (pl. LARVÆ).—The first condition of an insect at its issuing from the egg, when it is usually in the form of a grub, caterpillar, or maggot.