RECENT CAVE-DIGGING IN DERBYSHIRE. II5 



however, of numeroiis ' swallets ' on the divide, as well as in 

 other portions of the Carboniferous Limestone, at a considerable 

 distance from the impervious Yoredale Shales covering the 

 limestone, proves that the limestone did in ancient times receive 

 from the surface a considerable drainage which it no' longer 

 gets. Most of these ' swallets ' are now filled with clay and 

 loam, and some, as in the case of that at Windy Knoll, near 

 Castleton, about six miles to the north-east, contain consider- 

 able quantities of the remains of Pleistocene mammalia." 



Similarly, it must be granted that where there is now a hill- 

 top at Longcliffe, there existed, at the time when the swallow- 

 hole was active, a valley bounded by shales, and constituting 

 a gathering-ground for water. 



The question naturally arises : What caused the bones of so 

 many animals tO' be carried down intO' these swallow-holes ? 

 Messrs. Bemrose and Newton are very cautious on this point. 

 After suggesting several possible solutions, they favour the 

 conclusion (i) that there may have been an old hyaena den above 

 the swallow-hole, and that some of the bones may have been 

 carried by water out of it into the cavern where they were 

 found ; (2) that animals may have fallen into the hole itself, and 

 possibly through the roof of the cavern ; and, lastly, (3) that the 

 cavern itself may have at one time served as a hyaena den. 

 The second suggestion seems hardly probable when it is borne 

 in mind how very few unbroken marrow-bones were found. 

 Probably no record has been kept of the exact number of such 

 bones. The presence of a few gnawed bones and of " over 

 forty hysena-coprolites," gives support tO' the third hypothesis; 

 and the more or less complete stratification of the soil in which 

 the bones were deposited makes it probable that the first one 

 at least partly accoimts for the phenomena in question. 



But Professor Dawkins is much more decided about the 

 causes of what he found at Doveholes. After calling attention 

 to the fact that " the preponderance in the cave at Doveholes 



