OP WESTERN EUROPE AND THE MEDITERRANEAN COASTS. 
949 
From these and other considerations, the authors conclude that there seems to be in 
this agglomerate “ evidence not only of the former action of frosts severe enough to 
wedge out large blocks of limestone, but also of more or less sudden meltings of thick 
snow, such as would saturate heavy trains of debris, and cause them to move en masse 
down the steep slopes and over the lower grounds beyond.” This might be a true 
cause if the gathering ground had been larger and higher and the terminal slope less, 
but with so limited a gathering ground I do not see that it would be possible for 
snow, even if frozen, to hav-e accumulated in sufficient quantity as to be able to 
propel so vast a mass of debris, with blocks 12 feet in diameter, over the low^er 
slope, which dips at the small angle of 8° to 9^.'''' Even were it possible, would not the 
friction have been such as to cause the blocks to lose their sharp angles ? I have 
shown, also, that this projection of debris with blocks, occurs even where the 
gathering ground was of much smaller extent, the height less, and a snow-slide 
improbable. The later agglomerate they suppose to have been formed under similar 
cold climatic conditions after a long interval, during which the Rock had become 
inhabited, and the cave and fissure breccias had accumulated under the influence of a 
genial interglacial climate. 
The view I would take respecting the origin of the breccia may be briefly stated. 
First, however, with regard to the remarkable series of marine terraces, described 
by Mr. Smith, of Jordan Hill, at various levels up to 600 feet. Of these we have 
very insufficient information. We only know from his general statement that in the 
beach at Europa Point, on the level of 70 feet, he collected nearly 100 species of 
recent shells said to be such as now inhabit the Mediterranean, but no list is given. 
At a higher level he makes mention of an oyster bed and of Pectunculi, and then 
of a shelly bed, and of a bed with recent shells at the 600 feet level. But, wdth the 
exception of Pecten maximus and Patella ferruginea, no species are named. Although 
we cannot assign a date to these several terraces, it is probable that the one at 
Europa Point is of the same age as the one in the Channel. The others may go back 
to earlier Quaternary or Tertiary times and correspond with similar traces at high 
levels in different parts of the Mediterranean coasts. To determine their age we 
must wait for a better knowledge of their Molluscan fauna. 
On the emergence of the Rock, after the formation of these beaches, it became 
inhabited by wild animals, but there is nothing to show that this took place at an 
earlier date than the later Glacial or Post-glacial period, for the Mammalia are—with 
a few exceptions, due to the more southern situation of the Rock—of the same 
species as are common in the more northern caves. The predaceous animals found 
ready shelter in the caves and amongst the crags of the Rock, and there they may 
have carried the remains of the ruminants found in the older bone caves ; but it 
is difficult to suppose that the numerous Red Deer, Falloiv Deer, Oxen, and the 
vast numbers of Ibex spoken of by Falconer —the bones of which show con- 
* A more detailed section is given in ‘ Prehistoric Europe,’ p. 217. 
