196 The Philippine Journal of Science 1922 
almost invariably extinct forms, and the determination of the 
geological time during which they lived can only be made after 
much collection in many localities. In general, these extinct 
forms are the highly organized ones which have developed spe- 
cial adaptations particularly suited for their immediate envi- 
ronment. A slight change in climate, food, or salinity may be 
sufficient to cause such forms to become extinct or to develop 
other habits. New habits quickly, geologically speaking, may 
cause specific changes and a new species may result. The 
recognition of such evolutionary series of forms makes it pos- 
sible for the paleontologist to recognize comparatively small 
divisions of geological time, and its importance in oil and coal 
work is very great. In temperate latitudes these changes 
are marked; but recent work by the writer indicates that in the 
Tropics, where climatic changes have been but slight, evolution 
has proceeded much more slowly. As was stated above, the 
highly organized species make the best horizon determiners, and 
one fossil like Vicarya callosa Jenkins is of more value in 
horizon determination than several dozen others associated 
with this extinct but once widespread Asian species. Corals 
are highly specialized, and on this account they should prove 
particularly useful in the Philippines. 
ECONOMIC USES OF PALEONTOLOGY 
A few examples of the economic uses of paleontology will 
suffice to indicate that this study is important in practical ex- 
plorations for certain highly useful substances. In California 
an oil company was starting a well on a supposed anticline (up- 
fold). Sandstone on the west flank looked like the sandstone on 
the east, and the operators located approximately between the 
two flanks. A paleontologist examined the property, and he 
collected upper Cretaceous fossils from the west side and Mio- 
cene fossils from the east side, thus demonstrating that the 
oil operators were drilling not on the anticlinal axis but upon 4 
great fault, an ancient break in the earth’s crust, a very unlikely 
place for accumulation of oil. Long ago the Cretaceous strata 
had been moved upward hundreds of feet and the Miocene down- 
ward, faulting out all of the Eocene and Oligocene. This half 
hour’s work by the paleontologist caused the operators to save 
thousands of dollars, as failure was certain in this spot. 
_ For many years much time and money were spent in New 
York in search of coal, as the neighboring state, Pennsylvania, 
had an abundance. Hall, state geologist of New York, showed 
that the Paleozoic formations of New York were far older than 
