110 DAVIS: THE LAKE-DWELLINGS IN EAST YORKSHIRE. 
also were formed of oaken beams in a good state of preservation, 
joined together with greater accuracy than the former, and in some 
cases having their sides grooved or rabbeted to admit large panels 
driven down between them. The interiors of the chambers so formed 
were filled with bones and black moory earth, and the heaps of bones 
was raised up in some places within a foot of the surface." 
The animals whose remains were thus preserved were principally 
oxen, horses, asses, pigs, sheep, goats, deer, dogs and foxes. Some 
human bones were also found. 
Nearly one hundred lake-dwellings have been discovered in 
Ireland, and about the same number is recorded as having received 
more or less attention in Scotland ; of the latter fifty are entirely 
built of wood, and the remainder wood and stone combined or other 
materials. The Scotch Crannoges, in all essential particulars, are 
similar to those of Ireland, and were probably erected by the branch 
of the Celtic people who migrated northwards, whilst those of Ireland 
and Wales were the result of the influx of the Celtic element in its 
extension westwards. " The ordinary construction of the Crannoge 
proper" says Dr. Stuart " was by logs of wood in the bed of the lake, 
supporting a structure of earth and stones, or of a mixture of both, 
the mass being surrounded by piles of young oak trees in the bed of 
the lake, the inner row of which kept the island in shape, and the 
external rows acted as defences and breakwaters." Dr. Monro after 
prolonged investigation and experience was able to supplement the 
description given above as follows : — For defence and protection 
which I presume no one will doubt, were the primary objects of these 
islands, a small mossy lake, with its margin overgrown with reeds and 
grasses, and situated in a secluded locality amidst the thick meshes 
of the primeval forest of those days, would present the most desirable 
topographical conditions. Having fixed on such a locality the next 
consideration would be the selection of materials for building the 
island. In a lake containing the soft and yielding sediment due to 
decomposed vegetable matter, it is manifest that any heavy substance, 
as stones and earth, would be totally inadmissible owing to their 
weight, so that solid logs of wood, provided there was an abundant 
supply at hand, would be the best and cheapest material that could 
