522 



Abstract of Mr. J. Prestwich's Report on [June 20, 



The cave follows the course of two lines, or planes of joint, traversing 

 the limestone, along which the galleries have been excavated by the 

 long-continued action of water. Mr. Pengelly attributes the excava- 

 vation "to a stream of fresh water not subject to great floods, and 

 flowing constantly from the West Chamber through the Flint-knife and 

 Reindeer Galleries to the Steep Slide Hole." Mr. Bristow, on the other 

 hand, is inclined to attribute some portion of the formation of the cave to 

 marine action at a time when the land was lower. The same causes are 

 supposed by these gentlemen to have led respectively in eacli case to the 

 accumulation of the bed of shingle ; and as no shells are found in it, this 

 question has to be settled on other than palaeontological evidence. Both, 

 however, refer the cave-earth to subaerial action, Mr. Pengelly considering 

 it to have been chiefly carried on by running water, whereas Mr. Bristow 

 views it as mainly due to the erosion of the limestone, whereby the 

 calcareous portion has been dissolved and the insoluble portion left 

 behind as a red loam. In the same way Mr. Pengelly is of opinion that 

 the bones were likewise carried in from the exterior by the action of 

 running water ; while Mr. Bristow, like Mr. Busk, thinks that they are for 

 the most part those of animals which were carried into the cave to be 

 devoured. 



It is difficult to reconcile the conditions of the bones and their numbers 

 with their introduction by water ; for a large number are not at all worn, 

 and a great proportion of them show sharply graven marks of gnawing. 

 At the same time the local origin of the cave-earth cannot be admitted, 

 for the mass of limestone removed is quite insufficient to have formed so 

 large a quantity. Your reporter is of opinion that the bones were brought 

 into the cave by predatory animals, and that they are, in some cases, the 

 bones of animals which died there ; but he considers the cave-earth to have 

 been introduced by water,not by a constant, slow running stream, but by occa- 

 sional floods; for all the circumstances of the case seem to show that at certain 

 periods the cave was dry and at other periods flooded by fresh water, that 

 during the former intervals the cave was frequented by Hysenas which 

 brought in their prey to devour, and that with each successive inundation 

 successive collections of bones were covered up and imbedded in the 

 sediment with which the flood-waters were charged. The weathering of 

 some of the bones noticed by Mr. Busk is a weathering which may have 

 occurred in the cave ; for it is evident that all the bones were not at once 

 imbedded in the cave-earth, as there are some which are incrusted with a 

 thin coating of stalagmite that must have been produced by their lying for 

 a time exposed to the dripping from the roof before they were covered up. 

 Others, on the other hand, in places free from the dripping, would 

 weather to a certain degree, as they would weather on the surface of the 

 ground, according to the length of exposure. That the formation of sta- 

 lagmite, under certain favourable conditions, did proceed during the whole 

 cave-period is apparent from the section given by Mr. Pengelly, where at 



