



320 STRUCTURAL AND FIELD GEOLOGY 
conditions. Until recently few attempts had been made by 
competent botanists to subject the peat-bogs of this country 
to a like careful examination. Geologists specially interested 
in the later chapters of the stony record have for a long time 
believed that a rich harvest of results would yet be reaped in 
this promising field of inquiry. The purely geological 
evidence seemed to lead to the conclusion that the peat-bogs 
with their associated “forest-beds” belonged to a period 
during which several well-marked alternations of climate took 
place—the peat being the product of wet and cold conditions, 
while the “ forest-beds” indicated relatively dry and temperate 
conditions. The results recently obtained by Mr F. J. Lewis, 
in his botanical investigations into the composition and 
structure of our peat-bogs, have abundantly confirmed that 
conclusion. He has discovered distinct zones of Arctic plants 
in the peat of lowlands and highlands alike, and thus we can 
no longer doubt that the closing stages of the geological 
history of our islands were characterised by alternations of — 
cold and temperate climatic conditions.* 
* For a general account of Mr Lewis’s investigations see Science 
Progress, Vol. I1., p. 307. 

