( 99 ) 



very powerful stream it has in(>t (here with tlie ice stream coming 

 from Sweden and has [)ush3(l this back south-eastward in the direction 

 of Friesland, Groninghen and Drenthe." 



I wish to show first (hat the glacial cover of the Hondsrug in 

 Dubois's sense does not exist. For this it is sufticient to prove that 

 in various of the hiyhest places of the Hondsrug boulder-chi)' occurs. 



1^^. Moreover Dubois himself, in his second comnnmication, in 

 which numerous observations of the occurrence of boulder-clay i]i 

 South-Dreiite are enumerated, states its presence in various places in 

 the Hondsrug between Buinen and Exlo, it is true very near the 

 Eastern border but in the highest points of the Hondsrug (p. 102)'). 

 At a recent examination of tlie said section of the N. E. Local 

 Railway this also proved to me to be the case. 



2"'^. Boulder-clay occurs further at the highest point oftheHonds- 

 rug near Gasselte. There the N. E. L. R. cuts the ground to a 

 depth of 5 M, and at the same place where a bridge has been 

 constructed over the new railway (about the highest point of the 

 neighbourhood) a bed of boulder-clay 2 M. thick is found under a 

 thin sandy layer of vegetable earth. 



3'''^ Moreover I wish just to make mention of a clay-pit near 

 Zuidlaren, about J''/, K.M. outside the village, about 300 M. nortli 

 of the road from Zuidlaren to Vries. Though there the hilly character 

 of the Hondsrug is less distinctly to be recognized, it is easy to see 

 that the mentioned j)lace is one of the higiiest of the surroundings. 

 The clay-bed is 3 M. thick there. 



4'''. Finally 1 wish to remind the reader of the characteristics 

 in Groningen and south of it. Though the Hondsrug is hardly 

 noticed there, it is most characteristic as regards the shape. Well 

 then, there, in numerous places, boulder-clay occurs very often at 

 the highest places; on the borders there is usually more sand. 



I am not of opinion that from these observations, rather regularlv 

 spread over the Hondsrug, it follows that boulder-clay, quite contrary 

 to Dubois's opinion, should chiefly or exclusively occur at the highest 

 points. For a conclusion a most accurate and extensive examination 

 is required. 1 only wish, by the way, to call attention to an 



^) Slill Uic autlioi- sees no reason in tliis to drop liis liypolliesis, tliongli lie 

 says on p. 102 : 



"'! lie origin of llio Hondsrug according lo llio liypolliesis indicated in Die former 

 commnnieation can thus only lie applied to that western strip of honlder-clay", 

 1ml for the rest he maintains the opinion once pronounced as also appears IVom 

 his answer to Lorié's criticism cited before. 



