10S 
FIFTEENTH REPORT. 
the planet, water would pour down upon the hot material below, being 
vaporized at once. This vaporization must have continued throughout 
the action and condensation of the vapor in the upper atmosphere would 
produce rain in abundance and this rain must fall upon the crustal 
plateaus. 
The fragments of crust, standing two and a half or three miles high 
above the level of the hot denuded surfaces of the globe which are now 
the ocean bottoms would experience barometric changes which are 
difficult to predicate, but it seems clear that such altitude must have 
operated to lower the temperature very much as we observe it to do 
today. 
With the denuded areas hot and upward currents being engendered 
in the atmosphere the continental plateaus being meanwhile high and 
cool, it follows that the return currents would descend upon the plateaus 
bringing them rain and cold from the upper atmosphere. It is even 
supposable that snow might fall on peaks in the interior of a continental 
plateau notwithstanding the enormous amount of heat actually liberated 
from the denuded earth. So we see that there are three good reasons 
why life might survive. We are quite sure that it did survive and the 
objection would thus seem to be not a fatal one against the theory. 
3. LAND CONNECTIONS. 
Land connections where none now exist have long been postulated to 
account for numerous and curious relationships between widely separated 
groups of animals and plants. As long ago as 1853 Dr. Hooker in- 
sisted upon connections of Australia and New Zealand with Africa 
and South America to explain the distribution of southern plants and 
from that time on such connections have been largely introduced in 
all parts of the world. Heretofore it has been necessary to postulate 
numerous and extensive vertical movements of the earth's crust often 
without any real geological basis and even in spite of geological opposi- 
tion, and we must concede that such land connections as may have 
linked western Australia to South Africa, or South America to tropical 
Africa, or Spain to America, that these and similar examples are dis- 
tinctly opposed to what is known of isostatic geology. So it becomes 
of interest to inquire what effect this theory of the loss of earth mass 
may have on the conception of lost land connections the world over. 
Since in time the event is sharply localized to the end of the Cretaceous 
and the beginning of the Tertiary periods, and since it resulted in sub- 
stantially the present arrangement of the continents, clearly its prin- 
cipal effect is upon pretertiary geography. It is capable of explaining 
many of the distributional peculiarities of Tertiary and later time, but 
surely prior to that it involves a radical change in the globe upon which 
we may attempt to depict the relations of land and sea. 
So numerous and so difficult properly to weigh are individual in- 
stances of floral and faunal relationship that it seems best for me not 
to attempt to present and discuss any catalogue of such examples, striv- 
ing rather to deal in summaries by comparing current opinions with 
the new basis afforded by the theory to learn to what extent they may 
modify each other. 
The mechanical difficulties to be overcome have been found to be 
