102 Mr. H. H. Howorth on 



intercalated glacial periods, especially in the miocene, 

 pliocene, and permian eras, but no decided changes in the 

 character of the organic remains have yet been shown to 

 accompany the inorganic proofs of supposed glacial action 

 of those remoter periods {id. 202). 



Again, he says : " If the sketch we have given in the 

 tenth and eleventh chapters of the former states of climate 

 revealed to us by palaeontological research be an approxi- 

 mation to the truth, it will be at once seen that glacial 

 periods have not been perpetually recurring in the northern 

 temperate zone, as they ought to have done were a large 

 eccentricity alone sufficient, apart from the co-operation of 

 all other causes, to intensify the cold of high latitudes. It 

 was shown that the flora and fauna do not exhibit signs of 

 violent revolutions from hot to cold and from cold to hot 

 periods. On the contrary, the continuity of forces, particu- 

 larly in the class of reptiles, from the Carboniferous to the 

 Cretaceous period, is opposed to the intercalation of glacial 

 epochs corresponding in importance to that of post-pliocene 

 date. During the Carboniferous period there must have 

 been a long suspension in the temperate latitudes of the 

 northern hemisphere of cold such as we now experience. 

 An equable climate must have endured for a lapse of 

 centuries, sufficient to allow several giant cycles of eccen- 

 tricity to be gone through. But we do not find in strata of 

 that age 15,000 feet thick in Nova Scotia any proofs of such 

 intercalated glacial epochs. The peculiar vegetation of the 

 coal was persistent throughout the greater part of the ages 

 required for the deposition of so great a thickness of sedi- 

 ment in which one forest after another was buried on the 

 spot where it had grown "'{id. 299). 



On the same question, Professor Prestwich, who is facile 

 firinceps among English authorities on the tertiary period, 

 speaks even more emphatically : — " Dr. Croll shows," he 

 says, " that in the three million years for which his tables 



