280 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
than once man and his organic surroundings have been forced to 
wander into new regions; the life of cool to cold climates has dis- 
possessed that of milder temperatures, and with each moderation 
of the climate the hardier floras and faunas have advanced with the 
retreating glaciers or become stranded and isolated in the mountains. 
As the organic world is dependent upon sunlight, temperature, and 
moisture, it is not difficult to see why these same factors are essential 
to man and his civilization. 
PERMIC GLACIATION. 
Hardly had the Pleistocene glacial climate been proven when 
geologists began to point out the possibility of earlier ones. An 
enthusiastic Scotch writer, Sir Andrew Ramsay, in 1855 described 
certain late Paleozoic conglomerates of middle England, which he said 
were of glacial origin, but his evidence, though never completely 
gainsaid, has not been generally accepted. In the following year an 
Englishman, Dr. W. T. Blanford, said that the Talchir conglomerates 
occurring in central and southern India were of glacial origin, and 
since then the evidence for a Permic glacial period has been steadily 
accumulating. The land of ancient tills (tillites of geologists) is 
Africa, and here in 1870 Sutherland pointed out that the conglom- 
erates of the Karoo formation were of glacial origin, and, further, 
that they rest on a land surface which has been grooved, scratched, 
and polished by the movement of glaciers. Australia also has Permic 
glacial deposits. It is only very recently that the evidence found in 
many places in the Southern Hemisphere has become widely known, 
but so convincing is this testimony that all geologists are now ready 
to accept the conclusion that a glacial climate was as widespread in 
Permic time as was that of the Pleistocene. This time of organic 
stress, curiously, did not affect the polar lands, but rather those 
regions bordering the equatorial zone, while the temperate and arctic 
zones of the Northern Hemisphere were not glaciated, but seem to 
have had winters alternating with summers. The lands that were 
more or less covered with snow and ice lay on each side of the equator; 
that is, roughly, from 20° to 40° north and south of this line, as may 
-be seen in figure 2. 
Geologists now accept the geographical occurrence of tillite deposits 
formed in early Permic time as follows: Throughout South Africa 
(widely distributed and with much fossil evidence, thickness of tillites 
up to 1,130 feet); Tasmania; western, southern, eastern, and central 
Australia (tillites up to 1,300 feet thick, both land and marine fossils) ; 
peninsular and northwestern India; southeastern Brazil (of wide 
distribution, with land floras and some marine invertebrates) ; 
northern Argentina; and the Falkland Islands. ‘‘It may be added 
