s can be placed and conveniently brought under
the lens; and its height or that of the lens should be adjustable by a
rack-work; also a swivel-mounted little mirror beneath, which is needed
for minute objects to be viewed by transmitted light.

572. For dissecting and displaying small parts on the stage of the
microscope, besides a thin-bladed knife, the only tools needed are a
good stock of common needles of various sizes, mounted in handles, and
one or more saddler's-needles, which, being triangular, may be ground to
sharp edges convenient for dissection. Also a pair of delicate-pointed
forceps; those with curved points used by the dentist are most
convenient. A cup of clean water is indispensable, with which to moisten
or wet, or in which occasionally to float delicate parts. Small flowers,
buds, fruits, and seeds of dried specimens can be dissected quite as
well as fresh ones. They have only to be soaked in warm or boiling
water.

573. The compound microscope is rarely necessary except in cryptogamic
botany and vegetable anatomy; but it is very useful and convenient,
especially for the examination of pollen. To the advanced botanist it is
a necessity, to all students of botany an aid and delight.

574. =Analysis.= A few directions and hints may be given. The most
important is this: In studying an unknown plant, make a complete
examination of all its parts, and form a clear idea of its floral
structure and that of its fruit, from pericarp down to the embryo, or as
far as the materials in hand allow, before taking a step toward finding
out its name and relationship by means of the keys or other helps which
the Manuals and Floras provide. If it is the name merely that is wanted,
the shorter way is to ask some one who already knows it. To verify the
points of structure one by one as they happen to occur in an artificial
key, without any preparatory investigation, is a usual but is not the
best nor the surest way. It is well to make drawings or outline
sketches of the smaller parts, and especially diagrams of the plan of
the flower, such as those of Fig. 225, 227, 241, 244, 275-277. For
these, cross sections of the flower-bud or flower are to be made: and
longitudinal sections, such as Fig. 270-274, are equally important. The
dissection even of small seeds is not difficult after some practice.
Commonly they need to be soaked or boiled.

575. The right appreciation of characters and terms used in description
needs pra