LISTER : THE STUDY OF MYCETOZOA IN BRITAIN. 209
Our last intellectual treat was a visit to the Geological
Museum in Jermyn Street, which, although closed to the public
during the war, was opened to our party by special permission.
Here Dr. Strahan and Mr. Whitaker, in explaining the cases,
maps, and models, gave us in a few clear words the harvest of
a vast amount of observation and study, and enabled us to
find a new significance in familiar landscapes by describing
some of the processes which have helped to fashion the features
of our hills and valleys.
It has been a matter of much regret that our Secretary,
Mr. William Cole, has been unable, on account of continued
ill health, to be present at any but the first of our meetings
during the past year.
The subject of this address is chosen in response to a sug-
gestion, made here some time ago, that I should publish a list,
with descriptive notes, of the Mycetozoa recorded from Essex.
This list I have prepared, and I have prefaced it with a short
History of the Study of Mycetozoa in Britain.
These organisms, classed formerly with fungi, but now
usually regarded as belonging to the Protozoa in the animal
kingdom, are probably an ancient family. No fossil record
has yet been obtained of them, but this is not surprising, con-
sidering the almost ephemeral character of their sporangia when
subject to the usual wear and tear of wind and weather. Even
at the present day, with all facilities for hunting for Mycetozoa,
we find that special conditions and seasons are needed for their
perfect development and that in searching for them much
patience has often to be exercised. Yet we may still cherish
the hope that just the right combination of circumstances may
have occurred in the far past to lead to the preservation in
perhaps some ancient peat-bed of a bit of fossil wood bearing
tufts of the comparatively substantial columnar sporangia
of a Stemonitis, or clusters of round Trichia fruits, with their
spiral-marked elaters.
But, whatever may have been the distribution of Mycetozoa
in ancient days, we may picture with some certainty their return
to our island at the close of the last glacial period, when vegeta-
tion again appeared on the thawing ground as the ice retreated.
That these adaptable creatures sometimes thrive in a severe
climate is proved by many species having been found in high