Bulletin - United States National Museum - Smithsonian Institution

flora of washington and vicinity. 225
4. Making a herbarium.
The poisoDing of plants is the last strictly preservative process, and
we are now ready to consider the more advanced stages of botanical
work necessary to the orderly disposition of the plants identified, col-
lected, and preserved.
The usual course, upon which no useful innovation can be here pro-
posed, is to keep each genus, unless too large, in one folded sheet of
very heavy paper, called the "genus-cover," to be labeled with the
name of the genus on the lower left- hand corner, and to mount the
plants on fine white paper,. about IG by 11 inches in size, and place these
sheets in the genus-covers. The specimens thus prepared should be
kept in the latest api^roved order according to the natural system of
classification, in cases either permanently' made for the purpose or porta-
ble. These cases should consist of partitions, 13, or better, 14 inches wide.
4 or 5 inches high, and 19 inches deep, arranged one above another in sev-
eral vertical tiers; these dimensions to be all in the clear, and clear of door-
jambs. The doors, which should consist as much as possible of glass,
should, if practicable, be so hung that when swung back the edge will
be flush With the inner vertical sides of the cases, i. e., leaving no
shoulder for the genus-covers to catch upon in drawing them out.
The labeling of the orders is somewhat difiBcult on account of the per-
petually growing and changing character of the herbarium. If labels or
tickets are attached to the edges of the shelves, they are sure to require
removal in a short time, which disfigures the cases. The best arrange-
ment known to me to avoid these consequences and label the families is
that of portable order-covers. These consist of good, stiff boards (paste-
board) of the same width as the genus-covers and a little longer, to one
end of which flaps of the same material are attached by means of strong
binder's muslin pasted to both pieces, so that when the large board lies
on the package of genus-covers the flap will fall down over their ends
and present a vertical surface, upon which the name of the order or
orders in the package is placed. The flaps will be three or four inches
wide and as long as the board to which they are attached is wide. In
the course of time it will often happen that orders once jflaced in one
partition and labeled on the flap will have to be taken out and put in
another. In such cases the names must of course be erased from one
flap and writiten on another. The principal objection to this system is
that it requires time and trouble to remove the order-covers every time
a plant is wanted. Upon the whole, it is perhaps better to do without
Bull. Nat. Mus. No. 22 15