148
THE ESSEX NATURALIST.
even to the bottom in many cases, was highly recommended. In
addition to various forms of pocket magnifiers, a new contrivance
for viewing with simple lenses in the open air a tube or trough
containing aquatic organisms was exhibited and described. This
is designed to give the least possible trouble to the observer so
that it can, if required, be put into the hands of those who have
had no previous experience even of the use of a pocket-lens, and
at the same time it shows the objects very strongly illuminated
with a pleasing dark-ground effect.
Having now referred to some of the pieces of apparatus
which are either essential or occasionally useful for the collection
and examination of aquatic organisms, there remain for con-
sideration the various means by which the increased attention
to aquatic biology for which I am pleading may be fostered by
the members of a Field Club in their individual and associated
capacities.
As already mentioned, the need for additional workers who
will take up limited groups of aquatic organisms as their special
study is evident. The identification and recording of species
is essentially work that must be done by individuals, and one of
the most useful ways by which a member of a Field Club can help
his society is to become a specialist on at least one small group
of organisms, presuming of course that his expert knowledge is
placed freely at the disposal of his fellow-members. But here
the questions may be asked whether it would be better for the
individual who is thinking of taking up a special group, and for
his society, that he should specialize on one of what may be
termed the more popular groups (on which probably there will
already be a number of specialists in the society), or whether it
would be more advantageous to both if he selected one of the less
well-known groups. So far as the Field Club as a whole is con-
cerned, I think it would be much better for it to have only one
or a few specialists on each of as many groups as possible, in-
cluding of course the aquatic forms, than to have many specialists
on a very limited number of groups. The reasons for this are
that in the cataloguing of the fauna and flora of its area and in
any ecological work that the society may undertake it is sure
to want all the expert knowledge of all the different groups that
it can get, and that if such knowledge is to be found amongst its
own members its work will be very much facilitated. Further,
the value to its members of its meetings and discussions will
be greater the more the views of specialists on many branches