sential to all organisms. These include phosphorus, iron,
calcium, sodium, magnesium, chlorine, silicon.

As we examine more closely the structure and functions of organic
bodies, an extraordinary uniformity is apparent in all of them. This
is disguised in the more specialized forms, but in the simpler ones is
very apparent. Owing to this any attempt to separate absolutely the
animal and vegetable kingdoms proves futile.

The science that treats of living things, irrespective of the
distinction between plant and animal, is called "Biology," but for
many purposes it is desirable to recognize the distinctions, making
two departments of Biology,--Botany, treating of plants; and Zooelogy,
of animals. It is with the first of these only that we shall concern
ourselves here.

When one takes up a plant his attention is naturally first drawn to
its general appearance and structure, whether it is a complicated one
like one of the flowering plants, or some humbler member of the
vegetable kingdom,--a moss, seaweed, toadstool,--or even some still
simpler plant like a mould, or the apparently structureless green scum
that floats on a stagnant pond. In any case the impulse is to
investigate the form and structure as far as the means at one's
disposal will permit. Such a study of structure constitutes
"Morphology," which includes two departments,--gross anatomy, or a
general study of the parts; and minute anatomy, or "Histology," in
which a microscopic examination is made of the structure of the
different parts. A special department of Morphology called
"Embryology" is often recognized. This embraces a study of the
development of the organism from its earliest stage, and also the
development of its different members.

From a study of the structure of organisms we get a clue to their
relationships, and upon the basis of such relationships are enabled to
classify them or unite them into groups so as to indicate the degree
to which they are related. This constitutes the division of Botany
usually known as Classification or "Systematic Botany."

Finally, we may study the functions or workings of an organism: how it
feeds, breathes, moves, reproduces. This is "Physiology," and like
classification must be preceded by a knowledge of the structures
concerned.

For the study of the gross anatomy of plants the following articles
will be found of great assistance: 1. a sharp knife, and for more
delicate tissues, a razor; 2. a pair of smal