234 THE ESSEX NATURALIST.
can usually be recognised in this way are chiefly Collembola,
small Oligochaete worms and small mites, though occasionally I
have even been able to detect Harpacticid Copepods. But the
detritus from the washing is practically all that is required, for
it usually contains specimens of all the forms present, including
such as may have been seen by a preliminary search. Collem-
bola and sometimes the mites will be found on the surface of the
water containing the detritus.
For the actual washing I place the sample of leaf-carpet in a
jar about half full of water and then stir pretty vigorously. The
larger leaves are then removed and the remaining concoction
passed through a coarse sieve to get rid of the larger fragments
of leaves. So far I have used ordinary tap water for the
washing, but conceivably it would be better to use filtered rain
water as this would not be so likely to affect any organisms
sensitive to a change in the acidity of the medium to which they
were accustomed.
The next and final step is to examine some of the detritus
under the microscope, and I have made it a rule to do this as soon
as possible after the washing. For low-power examination a
small amount can be spread out on a glass plate, a lantern slide
cover being very useful for this purpose. For the higher powers
a small quantity can be placed on a 3" x 1" glass slip and covered
with a thin cover glass in the usual way, or it can be placed in a
live-box or other similar piece of apparatus.
If one were attempting to give a complete account of the life
of the leaf-carpet it would be necessary to include a good many
macroscopic as well as microscopic forms, for such things as
small snails, spiders, beetles, insect larvae, worms, etc., occur
pretty frequently. (For references to these larger forms see
especially 1 also 12, Chap. XIV.) But I have limited myself to
the microscopic forms of life and of these some sixteen different
groups have been found. The work I have so far been able to
do must be regarded as at most of only a preliminary character,
and it must be understood that the remarks made, both as to
the occurrence and relative abundance of the species recorded,
apply only to the forty or so samples actually examined. More-
over, practically all the work has been done on samples of leaf-
carpet from Epping Forest, though the latter fact makes it all