EARLY INVESTIGATIONS. 11 



"A third kind of peat ground has attracted my attention in ttie survey I 

 took of Brendeburg, Brunswic, and ShlesAvig: It is connected with lakes. 

 The bottom of every dale is a meadow on a subsoil of peat; this, by gradually 

 advancing into, contracts the original extent of the lakes; and, it is well- 

 known in that country, that many large lakes have been converted into 

 smaller ones, by the peat advancing from the original shores, and many places 

 now meadows, and only traversed by a stream, had still a lake in them, in the 

 memory of old people. 



"I have said that the peat gradually extends forward in these lakes, con- 

 tracting their surface. This is occasioned by the following causes. The 

 sandy sediment carried into these lakes by streams, gradually raises the bottom 

 of them. The consequence of this shallowness is the growth of common reeds ; 

 these are like the van in the progress; these advance forward as the bottom of 

 the lake is raised. No peat appears among the reeds, nor even among the 

 small aquatic plants which form a zone behind them. 



"2. Behind the zone of reeds, another rises up. It is distinct from the for- 

 mer and it is composed of different aquatic plants, as follows: Scirpus mariti- 

 mus, S. coespitosus, S. paudfloris, Equisetum palustre, E. flumatile, Eriophorum 

 polystachyon, and E. vaginatum; the last of which retains its form and appear- 

 ance longest in the remote peat. 



"3. Behind this zone, the conferva begins to embrace those plants with its 

 green clouds; this forms the bed in which the different species of aquatic 

 sphagnum grow; these thicken the matting, and favour the growth of common 

 moss plants, on the compact surface. 



"4. Behind this, another zone appears; it consists of the same kind of 

 plants; but these are so interwoven that the surface ismore compact and bears 

 more weight, though very elastic. On this zone some grasses appear. 



"5. Proceeding backward from this zone, the surface becomes more and 

 more compact; many kinds of land plants begin to grow over it, especially 

 when that surface, by being raised, is dry in summer. There the Ledum 

 palustre, Vaccinium oxycoccon, Comarum palustre, Erica tetralix, and various 

 kinds of grasses grow. Thus begins a zone on which cattle may pasture in 

 the summer. 



"6. From the beginning of this useful zone, still backward the ground 

 becomes more and more solid. This is the last zone that can be distinguished 

 by a decided difference in progress. 



"I have said before, that the succession of these different zones, from the 

 border of water towards the original border of sand, represents the succession of 

 changes that have taken place through time in each of the anterior zones, so 

 that, in proportion as the reeds advance, new zones are forming behind the 

 advancing reeds, on the same places which they thus abandon. That process 

 is more rapid in lakes which are originally shallower, and slower in deeper 

 lakes. It seems even to be stopped in some parts, where the reeds, which can 

 not advance beyond a certain depth, approach the brow of a great declivity 

 under water; there the progress, if continued, is not perceptible : But in lakes 

 originally not very deep, and in which the sandy sediments are advancing all 

 around, the reeds, forming a ring, gradually contracting its circumference, 

 meet in the center; and a.t last these reeds themselves vanish, so that instead 

 of a lake, a meadow occupies its surface. In some of these meadows, attempts 

 have been made to keep up a piece of water, but the attempt is vain, excepting 

 at a great expence: for luxuriant aquatic plants soon occupy that space, and 

 the peat, advancing rapidly, restores the meadow." 



