POSTGLACIAL, &>c, DEPOSITS OF CONTINENT 489 



growth of the bogs. 6th, The present appearance of the bogs 

 shows that the conditions have become less humid. 



Neolithic implements have been met with from time to time 

 in the Scandinavian bogs, generally not deeper down than two 

 feet or so, from which Blytt infers that in those bogs not more 

 than two feet of peat has formed within historical times. The 

 rate of growth of peat, like that of stalagmite, has been a much 

 disputed question — some holding that it forms very rapidly, 

 others that its growth is extremely slow. The fact is that the 

 growth is regulated by the supply of moisture and by climatic 

 conditions,, and the remarks made in a former page with reference 

 to the formation of stalagmites hold equally true of peat. Not 

 only does peat form at different rates in different regions, but 

 the same is often the case even in one and the same bog — the 

 bog being dry in some places, where it actually wastes and 

 crumbles away, while in other portions the mosses flourish more 

 or less luxuriantly. But even if it were true that peat accumu- 

 lated now at an equable rate throughout Northern Europe, still 

 that would not help us much in our endeavour to ascertain the 

 length of time required for the formation of our bogs. The 

 structure of the peat indicates the former prevalence of greater 

 humidity, during which moisture-loving plants nourished more 

 abundantly than under present conditions, and other things 

 being equal, the bogs generally must have increased more rapidly 

 then than they do now. Nothing, indeed, can be more misleading 

 than to take the known rate at which peat has accumulated in 

 some particular place as a standard of measurement by which 

 to judge of the antiquity of all other bogs. Steenstrup has 

 shown that peat in his country increases at so very slow a rate 

 that it is of no account in an economical point of view, and Blytt 

 is of the same opinion in regard to the peat of Norway. From 

 what he observed in Jsederen, he concluded that " when people 

 cut peat in bogs which had been cut by their fathers or grand- 

 fathers, it was obviously not peat formed in recent times, but 

 the old black peat, the cutting of which was formerly prevented 

 by the influx of water." I have often made the same observa- 



