30
THE ESSEX NATURALIST.
Our leaders and referees were:—
For mosses and hepatics .. .. .. Mr. W. R. Sherrin, A.L.S.
For lichens . . .. .. .. .. Miss A. Lorrain Smith,
F.L.S., and Mr. R.
Paulson, F.L.S.
For fungi and myxomycetes .. .. Miss G. Lister, F.L.S.
The route taken followed generally the course of the road leading
to the "Wake Arms," and thence along the Verderer's Path to High
Beach, but many detours were made to visit known stations for the rarer
forms or where some especially alluring prospect invited further explora-
tion. In perfect sunny weather, the party, which soon became split
up into small groups, each pursuing its own course, sought assiduously
for specimens, and many interesting and informal talks were given by
the referees on the finds. Lunch was as usual taken al fresco.
Arrived at the headquarters, the Roserville Retreat at Highbeach,
the re-united party took tea at 4.30 o'clock: following which, a meeting
of the club was held, with the President in the chair, when the several
referees were in turn asked to give their reports on the day's results.
Mr. Sherrin reported that a total of 43 mosses had been noted, of which
Eurhynchium abbreviatum was a new record for the Forest. Ten species
of hepatics had been found, including Ptilidium pulcherrimum in its
former station. Four forms of Sphagnum had been noted.
Mr. Paulson had listed 21 forms of lichens: he remarked that many
microscopic forms, such as Calicium, although certainly to be found, were
almost as certain to be overlooked, since they demanded detailed obser-
vation in order to detect them. Collema pulposum was one of the rarest
forms found that day, and was apparently a new record for the Forest.
Miss Lister presented no formal list of the fungi noted during the
day, but called attention to the great profusion of the handsome Fly
Agaric (Amanita muscaria) and of Armillaria mellea. Of the Mycetozoa,
which had engaged most of her attention during the ramble, twelve
species had been found, these being referable to as many genera. Two of
the most interesting forms seen were Dictydium cancellatum and Ener-
thenema papillatum. Miss Lister, at the President's request, went on to
give an account of some recently published discoveries with regard to the
nucleii of the myxomycetes made by Droege.1 She said:—
"The true Mycetozoa (Eu-mycetozoa) have been divided into two
subclasses, the Exosporeae and the Endosporeae; in the former the spores
are formed on the outside of membranous sporophores; in the latter the
spores are developed within the walls of a sporangium. The first group
is represented by the single genus Ceratiomyxa; to the second group all
the other true Mycetozoa belong.
"A spore of Ceratiomyxa, when first formed, contains a single nucleus
which, during the maturing process, divides twice; in the ripe hyaline
spore the four nuclei are clearly visible. In the Endosporeae the young
spore has also a single nucleus; the mature spore has a coloured and
often rather thick wall which obscures the contents, but when germination
takes place the emerging swarm-cell has a single nucleus this nucleus
1 See Jahn, Section, "Myxomycetes" in "Die Naturlichen Pflanzenfamilien," Band 2.306
(1928) and edition, edited by A. Engler.