8 
THE ESSEX FIELD CLUB. 
From Mount Nuolja, 3.900 ft., Torne Traske 
Sphtxvophonis covalloides Pers. Cladonia pyxidata Fr. 
Plalysma nivale Nyl. Cetvavia islandica Ach. 
Cetvavia aculeata Fr. Pavwielia saxatilis Ach. 
Squamavia nimbosa Fr. Solovina CYOcea Ach. 
Lecanova ventosa Ach. 
Many lichens can withstand great extremes of temperature, but, at 
the same time, identical species grow and fruit abundantly where the 
climate is extremely rigorous and also where the temperature in the 
depth of winter is seldom far below the freezing point. We find that 
most of the species now exhibited grow in such climates as those of Swedish 
Lapland, Central and North European Russia, at a height of from 7,000 
to 10,000 feet in the Alps, and in the south-western parts of Great Britain 
and Ireland almost down to the sea level. The lichens in this respect 
conform with Alpine flowering plants. Alpines come down to the sea 
level in Ireland, and various suggestions have been made to account for 
this. On the occasion of the International Phytogeographical excursion 
in Britain 1912, Professor Riibel suggested that it was a question of humid¬ 
ity. Professor Massart specifies among the features that struck him 
during the excursion, the mildness of the climate, and the presence of 
subalp ; ne and alpine species, at low altitudes. Quite recently, January 
1914, Mrs. Henshaw in a paper on the flora of Vancouver Island, read 
to the Linnean Society, stated that some alpine plants came down to a 
low level near the sea in parts of the island. 
Among the very interesting exhibits now on view in the Central Hall 
of the Natural History Museum, South Kensington, is one of animal 
and vegetable life in the Antarctic, showing some of the results of the 
Scott Expedition, 1910. There are a few lichens : one of them, Placodium 
muYovum, is a plant that is quite common in Cornwall and Devon ; it is 
also found in the Epping Forest area. 
In noting the distribution of lichens on tree trunks of our woods, it 
becomes quite evident that many species prefer either the south-east) 
south or south-west aspect. This may be owing to a preference for 
intense light. It would be very interesting to know whether the lichens 
on the birch trunks in high latitudes are more evenly distributed on ac¬ 
count of the fact that during the season when growth is possible the sun 
has a greater sweep round the trunks of trees than anything we get in 
England. No comparison, as far as one knows, has been made on the 
distribution of lichens on tree trunks in the south of England and in 
northern Scotland. 
CONVERSAZIONE. 
Saturday, 2ist February 1914. 
On the occasion of the conversazione at the Municipal Technical In¬ 
stitute, the Museum was thrown into the general exhibition space, and 
some special subjects were illustrated, under the direction of the Curators, 
Mr. W. Cole and Mr. H. Whitehead, B.Sc., and some members of the 
Essex Field Club. The Curators arranged in the Museum a set of Bee¬ 
hives and Bee-keepers’ appliances, and products, intended to illustrate 
