OF WESTERN EUROPE AND THE MEDITERRANEAN COASTS. 
961 
mountains behind. Retreat entirely cut off by projecting promontories on either 
side, the only paths yet open to the imprisoned herds were those that led to the caves, 
which were a little above the general level of the plain. Hither the animals must 
have thronged in vast multitudes, crushing into the caves and swarming over the 
ground at their entrance, where they were eventually overtaken by the waters and 
destroyed, and, as their bodies decayed,* a confused mass of their remains were left 
and scattered on and near the spot where they had finally congregated. 
For reasons before given, the land could not have remained long submerged. As 
it rose intermittently from beneath the waters, our supposition is that the rocky debris 
on the sides of the hills was hurled down by the effluent waters on to the pile of bones 
below, breaking them into fragments, and forming, together with them, the hetero¬ 
geneous mass of bones and rubble constituting the breccia. The last more rapid uplift, 
the effects of which are so frequently seen in many sections of the head, brought down 
the larger blocks of rock that now lie on the top of the whole. Scina, an independent 
witness, inferred from the character of the rock fragments, and from the red clay in 
which they are imbedded—and which comes from decomposed rock surfaces on the 
hills above—that, in the case of the Belliemi breccia, both the detritus and tbe bones 
had been washed down from Monte Belliemi. All this must have been effected in a 
space of time comparatively so short, that, though the bodies of the animals decayed, 
the bones underwent but little change, nor, encased as they became in an almost 
impermeable breccia, has the change they have since undergone been great. 
Thus there is, in all the essential conditions, a close agreement between this Sicilian 
breccia and the Rubble-drift of the south of England, as likewise with the rubble on the 
slopes of Mont Genay, of the Rock of Gibraltar, and of other places mentioned in the 
preceding pages. In all, the debris consists strictly of local materials ; the fragments 
are angular and sharp ; the bones are mostly in fragments, and are neither gnawed 
nor worn ; and the faunal remains are those alone of a land surface, and of species such 
as then were to be found in the district.! This rubble, also, forms in all these cases 
the last of the drift beds. The only apparent difference arises from the circumstance 
that, in the Sicilian area, the geographical configuration was that of a land-locked bay 
with many minor bays or embrasures in the front of the hill-range, so that, as the waters 
rose, the animals of the plain were driven together, as in a seine, into those bays, 
where, as a last resource, they sought shelter under the mural precipices and in the 
more accessible caves. As these precipices were nearly vertical, they formed, as the land 
rose again, a partial protection from the effluent currents, which otherwise might 
have carried the debris to a greater distance outwards. Under no other circumstance 
that I can conceive could the animal remains have been massed as they are at the 
foot of the escarpments encircling the plain of Palermo. 
It may be asked how could large herds of Hippopotami have existed in so limited 
* Some may have floated and so been carried to a distance and lost. 
t Scina seems to imply that on the slope of Belliemi land shells are associated with the breccia. 
MDCCCXCin.—A. 6 G 
