130 Reviews—The Glacial Anticyclone. 
Pleistocene glaciation. He adopts from paleontological evidence 
great climatic variations in the Mesozoic, but regards Neumayr’s 
Jurassic climatic belts as rather faunal realms. A universal warm | 
climate in the Middle Jurassic he claims from the far northern 
distribution of coral reefs and marine saurians, though why the 
saurians could not have lived in cold water, and the locality of the 
far northern Middle Jurassic coral reefs, is not stated. The identity 
of the tree ferns in Western Antarctica and Yorkshire does not appear 
to necessitate a universal warm climate, especially considering 
Hooker’s emphatic warning against trusting to ferns as climatic 
guides. The paper is of chief value as a summary of the opinion of 
one of the most competent authorities on paleontological evidence 
as to former geographical conditions. He concludes that there have 
been at least seven cool and four Glacial periods in the earth’s history, 
and that these were short in comparison with the intervening warm 
periods. In discussing the causes of the climatic changes he rejects 
volcanic dust as a primary factor, and also variations in the amount 
of carbon dioxide in the atmosphere. He regards the most probable 
cause as geographic changes due to rhythmic alteration in the earth’s 
topography, and he regards favourably the conclusion that there has 
been a periodic alternate heaping up of the ocean waters in the 
equatorial and Polar regions. He asks in conclusion, ‘‘ are we not 
forced to conclude’ that the earth’s shape changes periodically in 
response to gravitative forces that alter the body forms?” 
VIII.—Tue Guactat Anricyctonr.—The growing belief that the 
former glaciations are to be explained by changes in the atmospheric 
circulation and especially by the influence of great stationary anti- 
cyclones is supported in an interesting paper by Professor W. H. 
Hobbs, ‘‘ The Role of the Glacial Anticyclone in the Air Circulation 
ot the Globe” (Proc. Amer. Phil. Soc., vol. liv, No. 218, pp. 185-225, 
1915). Professor Hobbs is already well known as one of the upholders 
of this view, and he here discusses the bearing of the recent results 
from Antarctica and those collected by expeditions across Greenland 
which have not received adequate attention. Antarctica appeared at 
first opposed to this explanation owing to the belief that a great 
permanent cyclone lay around the South Pole. So strongly was this 
view accepted that Meinardus of the German Antarctic Expedition 
predicted that the interior of the Antarctic continent was bare and 
snowless. Meteorologists cling tenaciously to the South Polar 
cyclone. The results of the National Antarctic Expedition on this 
question were ambiguous owing to doubt as to whether the critical 
wind directions recorded were from the true or the magnetic south, 
directions which there are almost directly opposite. The work of the 
later expeditions has replaced the supposed South Polar cyclone by an 
anticline and has shown the existence of a powerful fohn effect around 
Antarctica, as is there also around Greenland. Professor Hobbs 
discusses the observations of the Swiss expedition under de Quervain, 
who in 1912 crossed Greenland from west to east between latitude 
66° and 68° N.; and of the German expedition under Koch and 
