ALTERNATE GLACIAL PERIODS 417 



the continuous shores of the Polar Circle, will account, on 

 the theory of modification, for many closely allied forms now 

 living in marine areas completely sundered. Thus, I think, 

 we can understand the presence of some closely allied, still 

 existing and extinct tertiary forms, on the eastern and west- 

 ern shores of temperate North America; and the still more 

 striking fact of many closely allied crustaceans (as described 

 in Dana's admirable work), some fish and other marine ani- 

 mals, inhabiting the Mediterranean and the seas of Japan, — 

 these two areas being now completely separated by the 

 breadth of a whole continent and by wide spaces of ocean. 



These cases of close relationship in species either now or 

 formerly inhabiting the seas on the eastern and western 

 shores of North America, the Mediterranean and Japan, and 

 the temperate lands of North America and Europe, are inex- 

 plicable on the theory of creation. We cannot maintain that 

 such species have been created alike, in correspondence with 

 the nearly similar physical conditions of the areas; for if we 

 compare, for instance, certain parts of South America with 

 parts of South Africa or Australia, we see countries closely 

 similar in all their physical conditions, with their inhabitants 

 utterly dissimilar. 



ALTERNATE GLACIAL PERIODS IN THE NORTH AND SOUTH 



But we must return to our more immediate subject. I am 

 convinced that Forbes' view may be largely extended. In 

 Europe we meet with the plainest evidence of the Glacial 

 period, from the western shores of Britain to the Oural range, 

 and southward to the Pyrenees. We may infer from the 

 frozen mammals and nature of the mountain vegetation, that 

 Siberia was similarly affected. In the Lebanon, according 

 to Dr. Hooker, perpetual snow formerly covered the central 

 axis, and fed glaciers which rolled 4000 feet down the val- 

 leys. The same observer has recently found great moraines 

 at a low level on the Atlas range in N. Africa. Along the 

 Himalaya, at points 900 miles apart, glaciers have left the 

 marks of their former low descent; and in Sikkim. Dr. 

 Hooker saw maize growing on ancient and gigantic moraines. 

 Southward of the Asiatic continent, on the opposite side of 



N— HC XI 



