THE GEOLOGIST. 
No'.v who can accept this as a satisfactory hypothesis of the forma* 
tion of these deposits ? It seems a needless labour to examine it in 
detail : it is incredible, upon the face of it, that the bone-breccias of 
these and numberless other caverns similarly circumstanced could 
have been accumulated in any such wa}' . 
But I feel very confident of being able to oSer an hypothesis -which 
v/ill meet all the ordinary facts of these cases, and against which on 
insuperable objections can be alleged. 
It so happened that, some years ago, I lived in company with a 
spaniel dog, I may almost say during every hour of its life, and in its 
daily habits I saw, uqIcss I am much mistaken, an explanation of the 
origin of the bone-breccias. Though a very small creature, it was 
an indomitable hunter ; no weather stopped it ; to range the fields, 
the woods, and the ditches surrounding them was its one passion. 
Wet, dirty, and tired it came in at dinner-time, and having eaten its 
meal, it lay down to sleej?. Upon awaking it began the operation 
which was surely enacted by the carnivora of the caves, and to which, 
as it seems to me, must be referred the curious mixture which now 
occupies their floors. "With its teeth it pulled the mud fi'om its long 
hair, and one would hardly have believed, had he not seen it, the 
heap of sand, clay, and pebbles which so small a dog left upon its 
rug. Had it been allowed to gnaw bones in the study — a delight 
which was forbidden — the ordinary materials of the breccias would 
have been complete — quite complete ; for it deposited more than one 
or two of its ovm. teeth, and abundance of its own hair, upon the floor. 
Nothing could better consist with the hypothesis thus proposed 
than the facts observed by M. Fontan. Of his two caves, one was 
from two hundred and fifty to three hundred feet nearer to the level of 
the valley than the other. There accordingly were found the larger 
pebbles. How certain it is that the larger prey would be taken to this 
more readily accessible den, and would bring in larger masses of 
mud, with larger stones fixed in them; and not unfrequently in the 
hoofs of the large dead animals — the aurochs, for instance — and in 
the feet of the carnivora themselves ; while in the cavern higher up 
on the hill, smaller portions, such as could be carried in the mouth 
without dragging, would more generally be disposed of, and with 
these smaller pebbles would be added to the accumulation, 
