1002 The American Naturalist. [December, 
Sicily, Germany, Russia and Australia. Many of these caves 
open by vertical fissures to the surface,and down these irregu- 
lar holes and chimneys the bones have been washed, while in 
some cases as at Wirksworth, in Derbyshire, England, or at 
the cave in the limestone at Port Kennedy, Pa., described by 
C. M. Wheatley, animals may have plunged into them and 
died in theirimprisonment. Once gathered in their final rest- 
ing place the process of burial goes on, in many cases rapidly, 
and in others slowly, and, according to the completeness of 
their sepulture, the condition of the bone is more or less per- 
fectly preserved. In river floods the animals or osseous debris 
borne forward in their waters are soon enveloped in the midst 
of the accompanying clay, sand, gravel and calcareous mud 
torn from the channel and banks of the stream. They sink 
to the bottom and are rapidly covered in by a rising blanket 
of deposition. In eaves and hollow receptacles the infiltrating 
streams bring constant additions of mud, and by their erosive 
action upon the surrounding limestone which they dissolve, 
they redeposit carbonate of lime through the interstices of the 
granular accumulation or form a hard layer above it, upon 
which again later ossuaries may be made, and the cave floor 
offer a study of separate and successive periods. 
Amongst the multitudinous details connected with the ex- 
ploration of caves for the traces and evidence of prehistoric 
man, the following facts have some reference to the fossiliza- 
tion of terrestrial vertebrates. A cave at Gailenreuth, Ger- 
many, contains an enormous quantity of bones and teeth of 
animals formerly living in its vicinity, and according to Dr. 
Buckland, introduced by a stream which passed through this 
chain of caverns in its subterranean course to lower levels. In 
the cave of Kiihloch, Germany, a black animal dust covers the 
whole floor to the depth of six feet, derived says the same 
authority “from comminuted and pulverized bone.” This 
accumulation is attributed to the use of the cave by bears 
through centuries." In the caves of North Wales near St. 
11 The habits of wild animals in resorting to caves is fully established by obser- 
vation. The custom of the panthers to make lairs of natural caves is i 
by Prof. Baird, and Major Pinto speaks of a circular chamber in a limestone 
‘mountain in Western Africa as a “regular haunt of wild beasts, as one might 
