ixXXlV PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



amid layers of mud and silt. We find such phosphates surrounding 

 some fossils, such as crustaceans from the London clay, leading us to 

 infer a connexion between the animal matter and this substance. 



We had a note from Mr. Farrer on Ingleborough Cave, accompa- 

 nied by a plan, in which its extension in the Great Scar limestone 

 beyond an old barrier of stalagmite, cut through in September 1837, 

 is shown. The length thus exhibited is considerable, and sand and 

 gravel of limestone and millstone grit are mentioned in the narrower 

 parts of the course of the cave. Basins of stalagmite occur, and the 

 accumulation of this substance is inferred to have forced the w^ater 

 flowing in the cavity into a new channel. The detailed study of caves 

 in limestone countries will frequently be repaid, independently of the 

 discovery of any remains of animals in them, by much information as 

 to their origin. Sometimes we find a crack or joint enlarged by the 

 removal of the carbonate of lime of the rock by means of free carbonic 

 acid in the waters flowing into them from the surface ; at others no 

 fissure or joint is apparent, and the loss of matter carried away in so- 

 lution has been effected in the space between two beds, or by the 

 gradual action of this cause from either fractures, joints, or planes of 

 bedding, in such a manner that the connexion between the hollows 

 of the cave and these fissures through which water can find its way 

 is out of sight. Limestone regions, as you are well-aware, from the 

 spaces between their joints and beds, which get gradually enlarged, 

 often swallow up rains, so that streams in them are few, the absorbed 

 water abundantly bursting out at some level beneath where the phy- 

 sical conditions are such that the waters can no longer freely descend 

 downwards. The replacement of carbonate of lime in these caves by 

 means of stalagmites and stalactites is another matter of interest. 

 These may be so continued as to fill up the greater part of such 

 cavities, cementing at the same time many a fallen mass of limestone. 

 So long as the fissures were replete with water flowing outwards at 

 some convenient level, the loss of limestone would continue, supposing 

 the presence of the needful carbonic acid ; but when by changes 

 effected, such as the elevation of the land relatively to the discharge 

 of drainage waters, the level preventing the escape of the water be- 

 came lower, and the atmosphere could enter the cave, the stalactites 

 and stalagmites would be formed, the component parts of which en- 

 tering slowly into the cavity would have been readily removed by the 

 water when it filled up the whole space. 



Geological Changes from Alteration of the Earth'' s Axis of Rotation. 



Respecting a possible change of climate resulting from a change 

 in the earth's axis of rotation, — an hypothesis which has from time 

 to time engaged attention as one which might serve to account for 

 the occurrence of organic remains, supposed to be those of animals 

 and plants requiring a higher temperature than that of the regions 

 where such remains are found, we have had two communications. In 

 one from Mr. Saull, he calls attention to the undoubted evidences of 

 the land being at intervals above and beneath the waters, and to 

 changes of temperature over the same area. These effects he attri- 



