Bulletin - United States National Museum - Smithsonian Institution

FLORA OF WASHINGTON AND VICINITY. 211
requisite appliances, even wliere it is necessary to work at wilted and
compressed specimens.
I need not say tliat a good microscope is indispensable, or repeat the
caution about supposing that a higli power is required. It is well to
have one with two or three lenses of different powers, and which may
be combined for very minute objects. What is known as the "Gray
microscope" is amply sufficient, and with certain improvements is about
all that is needed for systematic analysis. It should always be carried
in the pocket, separated, if need be, from the box that it comes in, and
which is used as a stand. Every botanist should have a pocket made
expressly for his glass, and should never be without it wherever he
may be. It is a great advantage to have a surface of some considerable
extent in front of the stand for tbe instrument and on a level with the
slide on which the object is to be i^laced. This is secured in the sim-
plest manner by laying down a book of the right thickness and using a
large piece of tin or sheet-iron in place of the glass slide usually j)ro-
vided. Upon this a whole plant of considerable size may be placed,
and the portion to be investigated brought under the glass. The steel
needles with handles, which usually accompany microscopes of this
class, are useful, but if broken or lost an excellent substitute is a thorn,
either from the cockspur thorn {Grata'gus Crus-galJi), or from the honey
locust {Gleditschia triacanthos). These wooden needles have the advan-
tage over steel ones that when wet they do not so iiersistently pick up
the small seeds, etc., which it is desired to put into position.
A young botanist's struggles with botanical keys can only be sympa-
thized with ; they can scarcely be aided by any general directions, and
there is no more effectual drill than the persevering effort to identify,
by the aid of a kej", a plant to which he has no clew. It should be the
ambition of every such beginner to analyze in this manner all the jilants
of his local flora. The more aid he receives from those who already
know their names and tell them to him, the more superficial will his
knowledge of botany be. It is the duty of his teacher, if he has one,
to give such suggestions as will guide him over the worst obstacles and
prevent discouragement, but he should never be told what his plant is.
In finding out the name of a plant for himself he must necessarily learn
much of its nature, and this information he will never again take the
trouble to acquire after he has once come into possession of the object
sought, i. €., its name. When he has learned this he imagines that he
Jcnows what the.plant is, and yet he does not really know what it is until