46 THE ESSEX NATURALIST.
mentation and to demonstrate or test for such things as hygro-
scopic valves and teeth, which are perhaps commoner than is
generally realised.
I use white cards upon which to fix the specimens, with strong
gum arabic, poisoned with a few drops of carbolic acid, and I
pin the cards to loose boards which fit easily into strongly-made
boxes.
It sometimes happens that neither gum nor any other
adhesive that I know will stick the fruit to the card but, with
very little extra trouble, a needle and thread will do all that is
wanted.
It is advisable to select specimens which have only just
dehisced, because in some cases the hygroscopic power, if any,
seems to reside in the superficial layers, and if these be abraded
it is easy to come to the wrong conclusion that there is none.
Thorough drying is essential before the specimens are ad-
mitted into the box, otherwise trouble will come in the shape
of mould and mites, spoiling the offender as well as other speci-
mens in the same box.
It adds to the usefulness of the collection to bisect a specimen
or two longitudinally, transversely, or both, in order to exhibit
internal arrangements by which the seeds are dispersed more
gradually than they would be otherwise. I have in my mind
especially the capsules of the poppies and of some members of
that very interesting family, the Caryophyllaceae.
With regard to the boxes in which I store the spent fruits
their colour is green, merely in order to distinguish them at a
glance from the black ones which hold the seeds. Each is divided
into two storeys by a loose board on corner supports, another
board fits loosely into the bottom, and they are strongly made
because there is nothing else to protect their fragile contents
from being crushed in the event of an accident.
I strongly recommend plenty of room being left to put new
acquisitions into their proper place : easy accessibility is abso-
lutely essential if the collection is to be consulted without waste
of time, and it can be preserved only by elasticity. When there
is no room in the right place it has to be found somewhere else,
which may be easy enough ; the trouble comes afterwards, for
it is very difficult as a rule to find what is wanted a week or
so after it has been put away in the wrong place, and very humili-