1904] CURRENT LITERATURE 221 
Vegetation of the Sihl valley. 
A portion of the Sihl valley about 8*" south of Lake Ziirich, Switzerland, 
is soon to be converted into a reservoir which will have an area of about 12°¢*™ 
the vegetation, particularly those which make this one of the most southern 
localities for a truly boreal moor-formation. As the most peculiar portions of 
the present vegetation will be completely destroyed and the surrounding regions 
consideralby modified, an important service has been rendered to science by 
Dr. Max Diiggeli in the presentation of a complete ecological and floristic study 
of the present vegetation.2 The completeness and care with which this work 
has been done make adequate review difficult. Among the unique features of 
the vegetation is the conifer forest (Picea excelsa) in the lowlands at an elevation 
which is characterized everywhere else in Switzerland by deciduous forests. The 
deciduous forests occur at higher levels along the valley slopes where there is 
better insolation, better drainage, and consequently warmer soil. 
he most widespread formation in the trough of the valley is the low moor 
(Flachmoor), while in several small areas the high moor or sphagnum bog (Hoch- 
occurs. Many samples of peat were examined and the vegetable remains 
identified. These showed that no essential change has taken place in the vege- 
tation since the last retreat of the ice, though remains of several species were 
found which do not now occur in the valley. Everywhere the samples showed 
that the low moor (Carex, Phragmites, Equisetum, Hypnum, etc.) is the pioneer, 
followed by the high moor (Sphagnum and its companions). The same suc- 
cession was found in the horizontal series. The author considers the most 
important factor in determining the occurrence of low moor and high moor to be 
pols dissolved salts in the water. He contrasts these formations as 
Bey tikes low moor develops where the water comes from the earth charged 
na aaa mineral matter. It is flat and centripetal. The high moor 
the ve 6 Sows only in soft water nearly free from minerals, is raised at 
ol saa a 1s centrifugal in development. Not until a considerable thickness 
test his h aROgE can the sphagnum get a start in the low moor. ‘oO 
tics high + eg as the mineral content of the water conditions the occurrence 
daily with a Pm € staked out ars of sphagnum 30°™ on a side, and watered 
Water from the ee Water containing minerals. Sphagnum watered on with 
MgCO,, Caco whi Tiver was killed in eleven days. Solutions of KNO,, Na;PQ,, 
a a i 3, €tC., gave A similar result. His solutions do not appear to have 
P On a very scientific basis, and he makes no mention of a control 
in whi ay Sak 
are Oia is similarly treated with a mineral-free water, but the results 
ve. 
Senet 
2 Du 
Sihltales epee mex, Pflanzengeographische und wirtschaftliche Monographie des 
8¥0. pp, 22 insiedeln, von Roblesen bis Studen (Gebiet des projektierten Sihlsees). 
w 222. PIS. 4. figs. 10. Zitrich: Zircher & Furrer. 1903. 
