on to all,) and qualified them as _Quercus bicolor_, _Quercus
rubra_, _Quercus alba_, _Quercus castanea_, etc., etc. His nomenclature,
being so easy of application, became at once exceedingly popular and made
him the great scientific legislator of his century. He insisted on Latin
names, because, if every naturalist should use his own language, it must
lead to great confusion, and this Latin nomenclature of double
significance was adopted by all. Another advantage of this binominal Latin
nomenclature consists in preventing the confusion frequently arising from
the use of the same name to designate different animals in different parts
of the world,--as, for instance, the name of Robin, used in America to
designate a bird of the Thrush family, entirely different from the Robin
of the Old World,--or of different names for the same animal, as Perch or
Chogset or Burgall for our Cunner. Nothing is more to be deprecated than
an over-appreciation of technicalities, valuing the name more highly than
the thing; but some knowledge of this nomenclature is necessary to every
student of Nature.

The improvements in science thus far were chiefly verbal. Cuvier now came
forward and added a principle. He showed that all animals are built upon a
certain number of definite plans. This momentous step, the significance of
which is not yet appreciated to its full extent; for, had its importance
been understood, the efforts of naturalists would have been directed
toward a further illustration of the distinctive characteristics of all
the plans,--instead of which, the division of the animal kingdom into
larger and smaller groups chiefly attracted their attention, and has been
carried too far by some of them. Linnaeus began with six classes, Cuvier
brought them up to nineteen, and at last the animal kingdom was subdivided
by subsequent investigators into twenty-eight classes. This multiplication
of divisions, however, soon suggested an important question: How far are
these divisions natural or inherent in the objects themselves, and not
dependent on individual views?

While Linnaeus pointed out classes, orders, genera, and species, other
naturalists had detected other divisions among animals, called families.
Lamarck, who had been a distinguished botanist before he began his study
of the animal kingdom, brought to his zooelogical researches his previous
methods of investigation. Families in the vegetable kingdom had long been
distinguished by