Bones discovered in a cave at Kirkdale, in Torkshire. 207 
waters of the same inundation that produced the diluvial 
gravel : these would enter and fill the cave, and there be- 
coming quiescent, would deposit the mud suspended in them 
(as we see daily silt and warp deposited in quiet spots by 
waters of muddy rivers ) along the whole bottom of the den, 
where it has remained undisturbed ever since. We cannot 
refer this mud to a land flood, or a succession of land floods, 
partly for the reasons before stated, and partly from the ge- 
neral dryness of the cave ; had it been liable to be filled with 
muddy water, it would have been so at the time I visited 
it in December, 1821, at the end of one of the most rainy 
seasons ever remembered ; but even then there were not 
the slightest symptoms of any such occurrence, and a few 
scanty droppings from the roof were the only traces of water 
within the area of the cavern. 
The 4th period is that during which the stalagmite was 
deposited which invests the upper surface of the mud. The 
quantity of this stalagmite appears to be much greater than 
that formed in the two periods during, and before which, 
the cave was tenanted by hyasnas. In the whole of this 4th 
period no creature appears to have entered the cave, with the 
exception possibly of mice, weasels, rabbits, and foxes, until 
it was opened last summer, and no other process of any kind 
appears to have been going on in it except the formation of 
stalactitic infiltrations ; the stratum of diluvial sediment marks 
the point of time at which the latter state of things began 
and the former ceased. As there is no mud at all on the top or 
sides of the cave, we have no mark to distinguish the relative 
quantities of stalactite formed on these parts during the periods 
we have been speaking of : should it however contain in any 
