In this way we determine the exact place of each animal. The dog belongs
to the kingdom _Animalia_, sub-kingdom _Metazoa_, class _Mammalia_,
order _Carnivora_, family _Canidæ_, genus _Canis_, species _Familiaris_,
variety _Hound_ (possibly) and its individual name, perhaps, is “Rover.”
The important thing is that the reader should have a picture of the
actual animal representing each class in his mind’s eye. He should
master the distinctions between the _great groups_, or classes, before
proceeding to a more minute classification.