Imago. The perfect (generally winged) reproductive state of an insect.
Implacenta (n.). A mammal having no placenta. (a.) Without a placenta, as certain marsupial animals.
Insectivorous. Feeding on insects.
Instinct (n.). Inward impulse; unconscious, involuntary, or unreasoning prompting to action; a disposition to any mode of action, whether bodily or spiritual, without a distinct apprehension of the end or object which Nature has designed should be accomplished thereby; specifically, the natural, unreasoning impulse in an animal, by which it is guided to the performance of any action, without thought of improvement in the method.
Invertebrata, or Invertebrate Animals. Those animals which do not possess a backbone or spinal column.
Isomeric (from Gr., equal and part). (Chem.) Having the quality of isomerism; as isomeric compounds.
Isomerism (Chem.). An identity of elements and of atomic proportions with a difference in the amount combined in the compound molecule, and of its essential qualities; as in the case of the physically unlike compounds of carbon and hydrogen, consisting one of one part of each, another of two parts of each, and a third of four of each.
Kangaroo. A ruminating marsupial animal of the genus Macropus, found in Australia and the neighboring islands.
Larva (plural 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.
Lemuridæ. A group of four-handed animals, distinct from the monkeys, and approaching the insectivorous quadrupeds in some of their characters and habits. Its members have the nostrils curved or twisted, and a claw instead of a nail upon the first finger of the hind hands.