332 Correspondence — T. G. Bonney — J. R. Dakijns. 



coniferous wood there j ast like that cat Stocklands, but no Ammonites. 

 I would suggest to local geologists the advisability of a persistent 

 search for the latter, A. M. Davies. 



25, Mortimer Street, W. 



NAMES FOR BRITISH ICE - SHEETS. 

 Sib, — To discuss fully the wide questions raised by Mr. Lamplugh's 

 reply to my letter of last April would require far too much 

 space, so I content myself with repeating that to propose a name 

 for that which has not been proved to exist is, to say the least, 

 premature. It is also objectionable, because so many persons cannot 

 become familiar with a name without assuming that it implies the 

 existence of a reality. As man is naturally prone to idolatry, which 

 in the present age commonly takes the form of phrase-worship, 1 am 

 sure that if the North Sea Ice-sheet passed without protest it would 

 quickly materialize into a geological fact. I had no objection to 

 using the term ' Scandinavian Ice-sheet,' because something of the 

 kind must have existed in that country, yet I was careful to speak 

 only of 'Caledonian ice.' So I cannot allow Mr. Lamplugh to 

 smuggle in an East British Ice-sheet under the cover of any phrase 

 in my letter. As for the late Glacial age of the Dogger Bank, that 

 of course is possible ; but T think whoever makes use of it as an 

 argument should indicate under what circumstances such a long 

 shoal-like mass of morainic matter was deposited in that position. 

 Also, I should like to have an explanation of the causes which would 

 lead to an exceptional precipitation of snow on any particular part of 

 a comparatively level plain which had considerable land masses on 

 three sides. My complaint against the school of glacialists to which 

 Mr. Lamplugh belongs is, that they insist on those facts which seem 

 to favour their ideas and ignore all which have the contrary effect. 

 Thus, like the defenders of the Ptolemaic system of Astronomy, they 

 support hypothesis by hypothesis, and invent epicycles to escape 

 from difficulties. It is, however, a gain to have it admitted that 

 boulders did not take an inside or outside passage on an ice-sheet 

 the whole way from Scandinavia to Eastern England. This 

 encourages me to hope that a course of sea-bathing early in the 

 Glacial Epoch may embolden some geologists to repeat the process 

 later in the same, and to extend southward the submergence which 

 must have occurred then (Geol. Mag., 1877, p. 72, and 1900, 

 p. 289) in a more northern region. T. G. Bonney. 



CURIOUS BRECCIAS IN THE HIGHLANDS. 

 Sir, — There are in the Scottish Highlands between Loch Katrine 

 and the upper part of Loch Lomond several bosses of diorite 

 surrounded by brecciated schist. These are very curious, for each 

 boss of diorite is surrounded by a narrow fringe of breccia consisting 

 entirely of schist without any admixture of igneous matter. It seems 

 to me that the diorite must have been forced up in a solid state 

 through the schist, which in consequence got broken up ; for had the 

 diorite been in a molten state when it came up, some of it would 

 surely have flowed among the fragments of schist. 



