A CONTRIBUTION TO THE FLORA OF THE COUNTY. 205
been carefully searched. Epping Forest, the district immediately
round Chelmsford, the neighbourhoods of Witham, Kelvedon
and Saffron Walden are the only parts at all thoroughly
explored so far, and even in these some as yet unrecorded
species, and especially varieties, will no doubt be discovered.
The whole of the eastern coast district in the broadest sense, the
Roothings, a large part of North Essex, and the whole of the
south from Shoebury to Grays and Purfleet, in which district as
the chalk crops up several unrecorded or rare species should be
found, have yet to be carefully searched; it is therefore plain
that in this direction much remains to be done.
2. The lack of diversity in the soils of Essex is another
point of importance, and this, together with the low elevation of
the whole of the county, has had a marked effect in lessening the
number of species likely to be found, and is a very real cause of
a poor Moss Flora.
3. The small rainfall of the county is another real cause not
only of a lack of luxuriousness in the growth of the species
occurring, but also probably of a smaller number of species being
met with than in the west of the country. The arboreal species
especially are poorly represented; the trees upon which they
usually grow are present, but it is seldom that one finds a moss-
grown tree, especially in the neighbourhood of London. This
may be due in part to the large amount of acid brought down by
the rain in many parts of the county, as Mr. Dymond has pointed
out in his paper on "Sulphate of Lime in Essex Soils and
Subsoils" (Essex Naturalist, xiv., p. 62).
The fruiting of mosses as a general rule appears to be most
abundant where the vegetative development is greatest, and we
find, as a rule, much less production of fruit by mosses in Essex
than we notice in the moister western parts of the country, where
the vegetative growth is more luxuriant. In this connection it
is worth noting that a considerable number of those mosses that
fail to produce fruit, or that fruit but seldom, frequently form
numerous small buds or gemmae, which are capable of reproduc-
ing the plant, as we see in Tetraphis pellucida, Tortula papillosa and
T. mutica (the leaves of which, like the last, are frequently covered
with numerous round gemmae), Orthotrichum lyellii, Aulacomnium
androgynum, and to a less extent A. palustre, or even reproducing,
themselves by a piece of leaf which breaks off, as in Campylopus