176 
PRESIDENTIAL ADDRESS. 
FACTORS PRODUCING UNIFORMITY OF TYPE. 
AMONGST AUSTRALIAN ABORIGINES. 
By W. L. CrgLíAND, M.B. 
(Read October 2, 1900.) 
of Part 3, descriptive of the Calabonna fossils. It is also 
pleasing to note that the value of the anthropological work 
men in Great Britain. This has led to a memorial being. 
sent to the South Australian Government and the University 
of Melbourne, that these two gentlemen might be allowed 
a further opportunity of studying the aboriginal habits and 
customs 1n Central Australia. It is N, gratifying to 
know that the authorities have seen their way to er 
ing the un and that the princely abet b of 
avid Syme, or the Melbourne Age, has supplied the nd 
sary funds. 
It may be or interes& to the Fellows of the ee if a 
Short space is devoted to the consideration of how there 
Continental dimensions of Australia, er ally the same 
type of features appears in parts se d by hundreds of 
miles To enquire why evolution, Viii | is always at work, 
has not produced qe diversity of type. 
It has been pointed out by Romanes, in his work, “Darwin 
and After Darwin," that evolution rests on a tripod con- 
sisting of Variability, Heredity, and Isolation. And that. 
evolution again is Ted qn > polytypie according to cer- 
tain definite conditions , further, that there is no 
evolution at all if free intererossing is allowed amongst all 
the members of the parent stock, and if isolation in any of 
its many forms is not mers. For, although there is a 
tendency to variability in each individual, yet heredity in the 
event of free intercrossing neutralises this tendency by the. 
