682 LCs GAN TLER ISIN, 
and in terms that need qualification. The idea hinges (1) on 
the action of the ocean as a reservoir of carbon dioxide and (2) 
on the losses of the organic cycle under the influence of cold. 
Cold water absorbs more carbon dioxide than warm water. As 
the atmosphere becomes impoverished and the temperature 
declines, the capacity of the ocean to take up carbon dioxide in 
solution increases. Instead, therefore, of resupplying the atmos- 
phere in the stress of its impoverishment, the ocean withholds its 
carbon dioxide to a certain extent, and possibly even turns 
robber itself by greater absorption, though the diminution of the 
tension of the carbon dioxide of the atmosphere as its amount 
is reduced tends to increase the discharge of carbon dioxide 
from the ocean to restore the equilibrium, and, to the degree of 
its efficiency which is undetermined, offsets the increased absorp- 
tion of the cold water. So also, with increased cold the process 
of organic decay becomes less active, a greater part of the 
vegetal and animal matter remains undecomposed, and its car- 
bon is thereby locked up, and hence the loss of carbon dioxide 
through the organic cycle is increased. The impoverishment 
of the atmosphere is thus hastened and the epoch of cold is pre- 
cipitated. 
With the spread of glaciation the main crystalline areas, 
whose alteration is the chief source of depletion, become cov- 
ered and frozen, and the abstraction of carbon dioxide by rock 
alteration is checked. The supply continuing the same, by 
hypothesis, reénrichment begins, and when it has sufficiently 
advanced warmth returns. With returning warmth, the ocean 
gives up its carbon dioxide more freely, the accumulated organic 
products decay and add their contribution of carbonic acid, 
and the reénrichment is accelerated and interglacial mildness 
hastened. 
With the reéxposure of the crystalline areas, alteration of 
the rocks is renewed and depletion reéstablished and a new 
cycle inaugurated. And so the process is presumed to continue 
until a change in the general topographic conditions determinesa 
cessation. 
