An attempt to Elucidate the History of the Irish Elk. 111 
a new set of tenants, of whom ourselves form a portion, occupy 
their places.* 
To sum up— 
1st.—The animals whose remains we find seem to have perished 
by miring, not in the lake mud or sediment, but by sticking fast 
in the bed of Lower Boulder clay, whose depressions were occupied 
by similar lakes. 
2nd.—That they lived during the deposit of the sands and 
gravels, or what is called the second stage of the glacial period, 
which possessed a temperate climate, and they consequently were 
interglacial ; and considering the extent of this deposit, the 
period must have been one of considerable duration. The clay 
marls seem to be of this age. 
3rd.—The top bed of clay, which I consider to be the Upper 
Boulder clay, seems arctic in its character. Hence, it is highly 
probable that the severe climate, by destroying the supply of food, 
killed off these animals, as well as others of the large Mammalia. 
It is also probable that the water-worn bones of these large 
animals found in the clays of England were individuals that had 
perished on the land, and whose remains were afterwards covered 
up by the clays and gravels. 
To my mind, Ballybetagh seems to be one of Nature’s note- 
books, where she jotted down in diminutive characters a record of 
the operations which she had been carrying on on a grander scale 
throughout the world. 
* 
* “We live in a Zoologically impoverished world, from which all the hugest and fiercest 
and strangest forms have disappeared; yet it is a marvellous fact, and one that has hardly 
been sufficiently dwelt upon, this suddenly dying out of so many large Mammalia, not in 
one place only, but over half the land surface of the globe. We cannot but believe that 
there must have been some physical cause for this great change; and it must have been 
a cause capable of actirg simultaneously over large portions of the earth’s surface, and one 
which, as far as the Tertiary period is concerned, was of an exceptional character. Such 
a cause exists in the great and recent physical change known as the glacial epoch. We 
have proof in both Europe and North America, that just about the time these large 
animals were disappearing all the northern parts of these continents were wrapped in a 
mantle of ice.” Wallace’s Geographical Distribution of Animals, vol. 1, page 150. 
