666 
president's address. 
Another interesting point is strongly brought out. Central 
Australia furnishes the most striking Australian instance known 
of the " potency of climate compared .with the inefficiency of 
physical barriers " in regulating geographical distribution. In 
an interesting address "On the Geographic Distribution of Life 
in North America," by Dr. Merriam, this author points out that 
Wallace* greatly underrates the importance of temperature as a 
factor in determining the distribution of animal life; and he adds : 
— " It is now pretty generally conceded that temperature and 
humidity are the chief factors governing the distribution of life, 
and that temperature is more potent than humidity." Australia 
is a continental tract, completely isolated, not reaching into very 
high or very low latitudes, without mountain ranges sufficiently 
high to reach the snow line, and its shores are washed wholly by 
tropical or temperate seas. It would seem that Merriam's 
dictum will not apply to the Eremian Region. In his important 
Presidential Address at the Sydney Meeting of the Australian 
Association for the Advancement of Science, Professor Tate 
said : — " The chief factors influencing the geographic dis- 
tribution of plants are those of temperature and moisture, 
because they are indispensable; of the two, so far as Australia is 
concerned, the latter is by very far the more important." This 
generalization is now shown to apply equally well to animal life. 
Finally, the Report furnishes confirmatory evidence as to the 
past history of Central Australia, as previously sketched by Prof. 
Tate and others. The elevated portions of the Larapintine 
region have continued to be land-surfaces since pre-Cretaceous 
times. They were insular members of the Archipelago whose 
shores were washed by the Lower Cretaceous Sea during the 
period of deposition of the Rolling Downs formation. During 
the deposition of the Desert Sandstone formation in Upper 
Cretaceous times they remained to some extent in the condition 
of islands, but the marine conditions had given place to a lacus- 
trine order of things. With a favourable climate and abundant 
Proc. Biol. Soc. Wash. vii. (1892). 
