MAN AND THE GLACIAL PERIOD. 



73 



is not only possible, but more probable. That other interpretation I 

 have indicated in the general section (Fig. 5), in which all the facts 

 observed are incorporated. I consider that the dark clay with vege- 

 table remains and bones of the large extinct mammals is preglacial, 

 in the sense that it is older than any of the glacial beds of the dis- 

 trict. The gravel below the "redbrick earth," in which Mr. Frere 

 found the flint implements, is probably of the same age, or that of 

 the overlying gravel (5 in Figs. 4 and 5). That the implements, and 

 also fragments of bones and wood, should be occasionally found in 

 the overlying deposits, is what might be expected, as they were in 

 great measure formed by the denudation of the older ones. The " red- 

 brick earth " (4 in section) is, I believe, a true glacial clay, belonging 

 to the latter part of the first European lake. It is a noticeable fact 

 that, all over Northern Europe, the glacial clays burn to a red color 

 a point not without significance w r ith regard to the red beds of Per- 







6 



Fig. 9. 1. Sandy "trail " with flints three feet. 3. False-bedded sand and subanguhr gravel-^fonr 

 feet six inches. 4. "Red-brick earth," yellow and unstratifled at top, graduating downward 

 into gray, laminated, calcareous clay ; shells of Bithinia tentaculata and Limnea palustris abuu- 

 dant at it? base, where there is about six inches of sandy clay four feet six inches. 6. Clay 

 similar at top to the lower part of the " red-brick earth," but with more chalk-grains, gradual- 

 ly more chalky downward, and with stones like the upper portion of the lower bowlder-clay at 

 poiut.il iu geueral section. 



mian or Triassic age. The false-bedded sands and gravels (3 in Figs. 

 4 and 5) belong, I think, to the middle glacial series, and the clay (2 

 in Figs. 4 and 5) is, I think, the upper bowlder-clay. These views are 

 only theoretical, but I claim that they are based upon as sound a 

 foundation, and are as much in accordance with the facts of the case, 

 as those generally received. 



Another interpretation is tenable, namely, that the lower bowlder- 

 clay underlies the brick-clays, and that the upper bowlder-clay over- 

 lies them, while they themselves belong to a warm interglacial period, 

 as held by Messrs. Croll and Geikie. I do not agree with this opinion, 

 as I can nowhere find any evidence of a warm interglacial period, and 

 am unwilling: to believe that there were more post-tertiary glacial 

 periods than one, when one will explain all the phenomena ; but if it 

 wex-e to turn out that the lower bowlder-clay does exist beneath the 

 brick-clays at Hoxne, it would be one of the strongest facts in its 

 favor yet brought forward. 



