CAVERNS AND THEIR CONTENTS. 457 
ditions eminently favourable for animal development, at least 
as regards size and proportions. 
In South America, however, as in England, the caverns were 
occupied, and these monsters lived when the land was smaller, 
not larger than at present. Much of the Avidth of those steppes 
that now conduct from the Atlantic to the foot of the Andes 
must then have been submerged, and have formed the ocean 
floor. The Andes were less lofty — the wall between the 
Atlantic and Pacific a less complete barrier than it has since 
become. The date of occupation of the caverns was one 
marked by great difference of climate, arising from great 
difference in the physical features of the land. 
In alluding briefly to three principal districts of the earth as 
affording special evidence concerning the cavern period, it 
must not be supposed that bone-caverns are confined to them, 
or that there is reason to suppose that the occupation was 
contemporaneous. It does, however, seem certain that from 
a time Avhen the present features of the land began to be 
de\ T eloped down to a very late period, when men began to be 
civilized, there existed many races of large animals that have 
been destroyed, and also that, during the long time that 
elapsed, very important and extensive changes took place in 
the relative level of land and water, and in the physical features 
of the land. 
The reader may be inclined to ask if any physical evidence 
exists of a sudden and violent disruption at any time of existing 
conditions, and a possible destruction of old and introduction 
of new races of animals. To this the geologist must reply in 
the negative. There is no such evidence in any part of the 
Avorld on a scale large enough to deserve attention. Local 
disturbances have probably been repeated frequently, but of 
any change affecting the AAdiole surface there are no indications 
whatever. 
Among the objects of interest found in caverns, those that 
have reference to the human race are naturally the most 
interesting. When, therefore, fragments even of the rudest 
kind that indicate human intelligence in their manufacture are 
met Avith in association Avith ancient bones, it is not surprising 
that much attention should be directed to the discovery. Few, 
however, hitherto, are the cases of this kind, except Avhen it is 
easy to refer the fragments to a definite period. Occasionally 
there have been found spear-heads and other articles of metal, 
small fragments of coarse pottery, and even beads, proAnng 
that the caverns had been for a time human habitations or 
sepulchres. All these, hoAvever, have reference to people of 
aaTiohl Ave knoAv that they had already advanced far in the pro- 
