86 : Reports and Proceedings. 
with the axes of the prisms, in the vertical columns, lying horizontal, 
and in other cases perpendicular to the surface on which the ice was 
formed. ‘The extent of these caverns was so large, the quantity of 
ice so great in proportion to the magnitude of the caverns, and the ice 
had been frozen at so low a temperature—being quite distinct from 
snow in any of its forms,~—that Mr. Browne’s attention was forcibly 
directed to discover, if possible, the cause of the phenomenon. He 
could find no satisfactory account in any of the works in which ice- 
caves have been alluded to; although it is evident that similar 
deposits have been met with in many other districts. ‘They have 
nowhere as yet been described in any detail, with the exception of 
the Glaciére near Besancon, which has been the subject of several 
communications to the French Academy, and the number is evi- 
dently very much greater than had been supposed. ‘They are locally 
known as affording abundant ice in summer. 
It is evident that numerous deposits of this kind cannot fail to 
have some effect on the caverns, and ultimately on the facilities 
afforded for natural drainage. Ice, forming and melting, must split 
still more widely crevices already existing; and sometimes, no doubt, ~ 
must form fresh cracks. The melting of the ice must carry down to 
great depths a constant stream of cold water during the summer 
months, and tend to modify the temperature of the rock, and reduce 
it below the degree that would otherwise belong to it. 
It is by no means easy to explain the origin of these accumulations. 
They may possibly be portions of old or modern glaciers entering 
the earth. This suggestion has not yet been verified; nor is it easy 
always to say whether at one place or other there may not be a 
communication with the day. ‘That in many cases the ice is pushed 
forwards and downwards to fill narrow cavities, there can be no 
doubt ; and that glacial effects are thus occasionally produced in the 
interior of the earth suggests some curious reflections. : 
The explanations offered and hitherto generally accepted with 
regard to ice-caves are utterly inapplicable in many of the cases 
cited by Mr. Browne. Evaporation cannot possibly have produced 
the effects observed. The accumulation of winter-snows is equally 
impossible. It remains that the whole of the caves should be re- 
examined geologically with a view to make out the exact conditions 
of the case. 
On THE DrvELOpMENT or Ammonites. By Dr. T. Wricut, F.G.S. 
HE analysis of the synonyms of certain species of Ammonites is 
very difficult, for these fossils have received different names 
from different writers, quite irrespective of the age, state of growth, 
or varietal form of the specimen described as the specific type. Not 
only do these fossils often supply imperfect or fragmentary palzonto- 
logical material, but many Ammonites have changed their form 
during growth; therefore the author collected specimens represent- 
ing the young, middle-aged, and old conditions of as many species 
as he could get together. The results of his observations on the 
