state of eccentricity, from the one hemisphere to the other. But 
all this depends on ocean-currents flowing from equatorial to 
polar regions, and the existence of these currents, in turn, de- 
pends, to a large extent, on the contour of the continents and the 
particular distribution of sea and land. Take, as one example, 
the Gulf stream, a current which played so important a part in 
the phenomena of the glacial epoch. A very slight change in 
on a former occasion, a change in the form or contour of the 
Northeast corner of the South American continent would have 
deflected the great equatorial current, the feeder of the Gulf 
stream, into the Southern ocean and away from the Caribbean sea. 
One of the main causes of the extreme condition of things 1M 
Northwestern Europe, as well as in eastern parts of America dur- 
ing the glacial epoch, was a large withdrawal of the warm waters 
of the Gulf stream, and this was to a great extent due, as I stated 
in my first paper on the subject to the position of Cape St. 
Rogue, which deflected the equatorial current into the Southern 
ocean. That a geographical distribution of land and water, per- 
i mitting of the existence and deflection of those heat-bearing cur- 
-  rentṣ is one of the main factors in my theory, is what must be — 
obvious to every reader of Climate and Time.” 
Dr. Croll maintains that, with the exception of those resulting 
from oscillations of sea level, the general distribution of sea an 
nd and other geographical conditions were the same during the 
_ glacial epoch as they are at present. Thus he does not accept 
Lyell’s theory of an elevation of northern lands; yet we do not 
see but that this was a matter of fact. Indeed, Mr. Croll’s specu- 
lations produce the impression that he is somewhat one-sided in 
his treatment of these theories. His knowledge of general geol- 
ogy, and especially of palzontology, is apparently slight. For as 
_ regards his theory of interglacial climates in times preceding the | 
vcs Quaternary, the view is opposed to the whole »mass of facts 1n 
~ palzontology. The more we have read of Dr. Croll’s eccentricity 
_ theory, the less necessary does it seem; the geologist had better 
: 1 Philos, Mag. for August, 1864. 
