396 Searles 7. Woody Jun. — The Climate Controversy. 



TJnio litf oralis, and of such mammalia as the Mippopotamus. and other 

 great pachyderms, and of such a littoral Lusitanian fauna as that of 

 the Selsey bed, where it is mixed up with the remains of some of 

 these pachyderms, as well as of some other features, such as that of 

 the Lexden bed,' it has seemed to me that the climate of the earlier 

 part of the Post- Glacial period in England was possibly even warmer 

 than our present climate ; and that it was succeeded by a refrigera- 

 tion sufficiently severe to cause ice to form round all our coasts, and 

 glaciers to accumulate in the valleys of the mountain districts ; and 

 that this increased severity of climate was preceded, and partially 

 accompanied, by a limited submergence, which nowhere apparently 

 exceeded 300 feet, and reached that amount only in the northern 

 counties of England. To this refrigerence, it seems to me, the Hip- 

 popotamus early succumbed ; but the other pachyderms struggled 

 on, eventually to succumb to it all over Europe and North Asia, so 

 that they all co-existed, more or less, with the Arctic mammalia. I 

 do not recollect having met with any notice of the coincidence, but 

 it has struck me as significant, in reference to the view that the 

 pachydermata thus owe their extinction to Post-Glacial refrigeration, 

 that it is for the most part those Post-Glacial mammalia which all 

 palaeontologists admit to be specifically different from their living 

 representatives, which are represented by inhabitants of warm 

 climates ; whereas, on the opposite hand, those Post-Glacial mam- 

 malia that are specifically identical with living forms are repre- 

 sented by inhabitants of climates where there is a considerable 

 degree of winter cold. ^ 



To the extent thus explained there seem to me to have been 

 alternations of climate in England connected with the close of Geo- 

 logical time, whether we call them Glacial or Post-Glacial, Tertiary 

 or Post-Tertiary ; but they do not appear to be precisely such suc- 

 cessive alternations of hot and cold periods, accompanied during the 

 latter by general submergence, as the Excentricity theory demands. 



Proceeding on this assumption that during periods of great excen- 

 tricity the hemisphere in which the aphelion occurred during winter 

 would not only be glaciated, but be subject to submergence, in con- 

 sequence of the attraction of the ice-cap drawing the sea towards it, 

 and away from the opposite hemisphere, where it produced emer- 

 gence, Mr. Croll endeavours to show that the Coal-seams of the 

 Carboniferous formation are due to interglacial periods of warmth. 

 His view is that during these warm periods, when the land emerged 

 by the sea being drawn away from it, a very equable climate pre- 

 vailed in consequence of the sun being, while the excentricity was at 



^ The insect remains from Lexden, one of the numerous Post-Glacial brick-earths 

 of England, were considered by Mr. "Wollaston to indicate a warmer climate than 

 our present one. — Q. J. G. S. vol. xix. p. 399. 



2 For the grounds of the views thus summarized see papers in the following, viz. 

 Quart. Journ. of the Geol. Soc. vol. xxiii. p. 394, vol. xxiv. p. 146, vol. xxvi. p. 90, 

 vol. xxvii. p. 3 ; Geol. Mag. Vol. VII. pp. 17 and 61, Vol. VIII. p. 406, Vol. IX. 

 pp. 153, l7l, and 352. I hope at a future time to explain in more detail the evi- 

 dence indicative of the Post-Glacial submergence referred to in the text, which is 

 that to which the Hessle Clay of the North-East, and the Upper Boulder-clay of 

 the North- West of England are in my opinion due. 



