462 PREHISTORIC EUROPE. 



shown by the occurrence of large trunks in bogs at elevations 

 above 1000 and 1200 feet. 2d, Subsequently mosses and other 

 peat-producing plants began to grow and nourish, stopping the 

 drainage, killing the trees, and gradually enveloping them as 

 they fell. 3d, In this manner the low grounds became dis- 

 forested over wide areas, wherever, indeed, the peat could easily 

 accumulate ; but on low hills, in the bogs, the oak still con- 

 tinued to grow. 4th, By and by the growth of peat ceased, and 

 forests, principally of deals, sprang up on the peaty surface, and 

 continued to flourish for a long time contemporaneously with 

 the oaks that covered the hills or " islands " in the bogs. These 

 hills, Mr. Kinahan says, " although now destitute of trees, are 

 still called derries (Anglice, oak-woods), the ancient name, which 

 has survived down to the present day, probably from the time 

 when they were oak-groves, surrounded by forests of deal. In 

 some of the wilds of Mayo the oak may still be found growing 

 on the drift-islands in the bog, it always being associated with 

 yew, hazel, birch, ash, and holly ; probably the last three kinds 

 of trees were also denizens of the primary forests, but their 

 timber has long since disappeared, they being of kinds that rot 

 quickly in the bogs." 5th, A second epoch of peat-growth suc- 

 ceeded, during which the deal forests succumbed in the same 

 manner as the oaks had done at an earlier period. 



Human relics have frequently been discovered in the Irish 

 peat-bogs. Mr. Kinahan mentions the occurrence of a two- 

 story log-house under 14 feet of peat in Drumkelin Bog, Inver, 

 County of Donegal. It rested upon a thickness of 15 feet of 

 peat, making in all 37 feet, " over 22 feet of which must have 

 grown around and above the house since it was inhabited. On a 

 level with the floor of the house were the corkers (stumps) of sallow, 

 ash, and oak ; while in its vicinity a piece of a leather sandal, a 

 flint arrow-head, and a wooden sword, were subsequently found." 

 Human bodies, clad in woollen and hair garments of antique 

 fashion, have also been now and then discovered at various 

 depths in the bogs. Old roadways, formed of timber, have like- 

 wise been observed. In one case (Duncan's Flow-bog, Bally- 



