EEPOET ON THE ENPLOE AT ION OE BEIXHAM CAVE. 
553 
VIII. General Conclusions respecting the Cave. 
The main object of this investigation is necessarily to put on record, in a form available 
for future examination, information of that special and exact character which, from the 
costly nature of the work and the variety of subjects connected with it, places it gene- 
rally beyond individual research. It could not, in this case, have been carried out but 
for the liberal and timely assistance of the Royal Society and the cooperation of several 
members of the Committee, each taking a separate department. The able papers accom- 
panying this Report describe in minute detail the structure and contents of a new and 
unexplored bone-cave. As before mentioned, the questions of theory will be restricted to 
those alone which are suggested by the local nature of the phenomena, some of which 
have, however, an important bearing upon the general question of ossiferous caves. 
All observers agree that the cave follows the course of the two lines or planes of joint 
traversing the limestone rock, and that the galleries forming the cave have been exca- 
vated or worn along these lines of joint by the slow and prolonged action of water. Mr. 
Pengelly further points out that two sets of side grooves extend through the length of 
the cave with a dip inwards to one point, whence he infers its action at two successive 
levels, and that “each pair of grooves seems to be distinctly referable to a stream of 
fresh water which was not subject to great floods, and which flowed constantly from the 
West Chamber through the Flint-knife and Reindeer Galleries to the Steep Slide Hole, 
and the bottom of which was successively on the plane of the lower margins of the 
grooves themselves ; while another stream came in at the road entrance and flowed to 
the same Hole.” 
Mr. Bristow, on the other hand, inclines to attribute some portion of the formation 
of the cave and the introduction of the shingle to marine action, at the time when the 
land was lower, and when, by the same marine action, the present valley was being exca- 
vated ; and he observes that “ the grinding-action of the waves and shingle may have 
assisted in widening a preexisting fissure and joint in the limestone, and have tended 
materially to increase the dimensions of those parts of the cave which were being formed 
by atmospheric influences, coupled with the flow of water resulting from the filling and 
emptying of the cave at every change of tide and in his communication to the Com- 
mittee he points to the fact that the “ pebbles of quartz, rounded fragments of the slate 
rocks of the district, &c. (forming the pebble bed in the cave) are precisely similar in 
character and appearance to those forming the raised beach visible on the neighbouring- 
coast, as well as to the shingle on the shore of Mudstone-Bay sands north of Brixham.” 
Mr. Pengelly considers that, in the case of the side grooves just referred to, “ the tides 
and waves could not have allowed the preservation of levels so restricted,” and that in 
confined spaces like the narrow galleries of a cavern, the waves of the sea would have 
arranged the materials differently to what they would on an open beach. There is an 
entire absence in the cave-shingle of shells, whether marine (such as would prove the 
presence of the sea) or freshwater (such as might be introduced by the action of a running 
stream). Fragments of the former would have been more likely to have been preserved 
4 e 2 
