68. PRESIDENT’S ADDRESS—SECTION C. 
STRATIGRAPHICAL SYNCHRONISM DEMONSTRATED BY PuysicaL 
PHENOMENA. 
Huxley writes :—‘ There seems no escape from the admission 
that neither physical geology nor paleontology possesses any 
method by which the absolute synchronism of two strata can be 
demonstrated” (op. cit., p. xlvi.). This supposition neglects the 
evidences of vast alteration of the physical geography of the 
globe, which is implhed by the extinction of the Carboniferous 
and Cretaceous fauna, and their replacement by equally rich 
and varied fauna, but of totally different types. 
Again, Oldham has shown a climatic conformity at two geo- 
logical horizons in South Africa and Australia, and that the 
palzontological features are similar in each of the series in 
which the intercalated glacial phenomena are exhibited. 
ORIGIN OF SIMILAR CONTEMPORANEOUS FAUNA. 
My conception of the origin of the similitudes between con- 
temporaneous faunz of distant areas, which is, however, depen- 
dent on the hypothesis of permanency of continental areas and 
deep oceans from very early times, may be briefly stated as fol- 
lows :— 
1. There was a uniformity of life at the beginning, that is, as 
soon as the temperature permitted life to exist, because of a pre- 
vailing uniform climate. 
2. On the formation of the nuclei of the continental masses 
evolution of the primitive forms commenced ; but with increasing 
growth of the land areas and differentiation of climate, divergence 
from the main lines of evolution occurred in varying degrees 
according to the greater or less diversity of the conditions 
in one area as compared with another. In other words, each 
juvenile continental mass became a fixed centre, around the cir- 
cumference of which the ancestors common to all underwent 
modification, so that centres of creation, as it were, were set up 
around the growing land-masses; from these have developed 
in more or less parallel lines of divergence similar, but not identi- 
cal, faunas, characteristic of each area throughout successive 
epochs. The growth of these ofi-shoots would depend upon cir- 
cumstances, and in some centres at different epochs the initial 
force which caused them to bud forth was feeble, and the environ- 
ment uncongenial to the evolution of species, or of higher types. 
Such contrast is presented by the Upper Cretaceous fauna of 
Australia and Western Europe, and by that of the Ordivician in 
the same areas. 
