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Society for the Reclaiming of' Heaths, I make the following remark. 

 Through the kindness of the Direction I was enabled to consult the 

 original registers together with the maps, relating to the borings, and 

 afterwards controlled these in situ. I ascertained, by many contnjlling 

 borings, that the borings of the Society are lying too far apart to 

 give an approximately exact idea of the presence and distribution 

 of the loam; besides tliat it is decidedly incorrect to state that "red 

 clay especially occurs on the Hondsrug and chiefly in its highest parts". 



The other solution, which I suggested, in a second paper dealing 

 with the Hondsrug, as a possible explanation for the origin of the 

 longitudinal vaulting of the ridge (an explanation which is independent 

 of the distribution of the boulder-clay and boulder-sand and which 

 at the same time throws some light on the origin of the strange, 

 round hill "Brammershoop"), which Dr. Jonker leaves unnoticed. 



I believe to I have given already sufficient reasons for the opinion 

 I hold, that, generally speaking, boulder-clay and boulder-sand have 

 been, from the first, two distinct kinds of deposits, and that the 

 latter has not proceeded from the former. I will only add, that to 

 Dr. Jonker's statements "that the percentage of stones in the boulder- 

 clay increases very much towards the surface", I can oppose the 

 results of other and, I believe, more extensive statements, where 

 either the reverse was the case, or the stones were uniformly distri- 

 buted. This disparity is easil}^ explained from the great local diffe- 

 rence in that quantity, justly observed by Dr. Jonker. 



The vanishing of limestone-boulders does not prove the washing-out 

 of the loam, for it may have been occasioned by solution alone, without 

 washing; calcarious pebbles, originally present in clay or sand, may 

 disappear when the underground-water is not saturated with bicarbonate 

 of lime, and they may be preserved when this is indeed the case. I wil- 

 lingly allow that the reason why, for instance, the clay of the Mird urn- 

 Cliff is especially rich in absolutely unmodified calcarious stones (the 

 finest scratchings have been preserved), and that on the contrary, in 

 other parts, not a single calcarious pebble is found in similar clay, 

 need not be attributed to local differences in the original composition 

 of the ground-moraine. But this cannot be said with regard to the 

 flints, and especially not in respect of the clay itself. Clay of the 

 tough kind, called boulder-clay, is a very resistant substance. Expe- 

 rience in the field teaches that there can be no question of a wash- 

 out of particles of clay from a similar mass. The motion of the water 

 through the clay is far too slow for it. If Dr. Jonker had more 

 frequent opportunities of studying boulder-clay and sand abroad, 

 especially in England, he would, undoubtedly, have modified his 



