president’s address. 
239 
of level, &c. For example, the fact pointed out by Mr. Ball 
that of 1,157 species of plants characteristic of the Alps, two- 
thirds are found in the Carpathians, one-half in the Pyrenees, 
and one-fourth in the Altai, is clearly of much importance in 
determining the physical conditions to which those mountains 
have been subjected. Then, again, under what circumstances 
did plants like the Astrantia major at Stokesay, and the 
Potent-ilia rupestris at the Breiddens, find their way to those 
localities ? The former is found not nearer to Britain than 
Central France, and yet it occurs rather abundantly in the 
woods over Stokesay Castle. Is it the sole survivor of an 
extinct flora, or has it been conveyed hither, as has been 
supposed by some—perhaps accidentally—in the time of the 
Roman occupation ? I am glad to see that, at the last general 
meeting of the Midland Union, a vigorous effort was set on 
foot to check the reckless destruction of rare plants, and to 
co-operate with the society which has been formed in France 
for this special purpose. 
In relation to some of the lower forms of vegetable life, 
much attention is being paid to them by several of our local 
botanists, under the stimulus of the Microscopical Society which 
has been formed in this town. A few years ago a committee 
was appointed by the Caradoc Club to obtain information upon 
a curious phenomenon which occurs in some of the numerous 
lakes of greater or less size which are situated in the north of 
this and the adjoining parts of the border counties. At certain 
seasons the water becomes extremely turbid, making it useless 
for household purposes, and so uncomfortable for the fish that 
they refuse to take any bait. The result of these investigations 
has been an able paper by Mr. Phillips, published in the 
Transactions of the Arclneological Society. It soon became 
evident that the “ breaking of the meres,” as the phenomenon 
is termed in the district, was due to the appearance at certain 
seasons of minute algae in enormous quantities. These have 
been fully described by Mr. Phillips, and include the following: — 
Rivulciria articulata , Anabcena circinalis, Ccelospheriimi Kutziiuji- 
anum, Dolichosperrnum Ralfsii, Aplianizomenon Flos-aquai. It is 
remarkable that while in some of these meres the breaking 
lasts sometimes during a considerable part of the year, in 
others it is much more rare, and one has never been known to 
break, although connected by a wide ditch with the next one, 
which is conspicuous for doing so. I have further to report 
the discovery by Mr. Beckwith of Nitella gracilis, an alga which 
had previously been recorded only for North Britain and Ireland. 
Mr. Phillips is devoting his attention to the fungi especially, 
and a list of the Hymenomycetes of the county has already 
