179 
Herepity.— Variability would not be of much use in evolu- 
tion where it not n physical characteristics can be trans- 
mitted from parent t offspring. A tendency to variability 
will exist in all organisma; —€——" the amount o t 
be either a help or à hindrance to evolution, as has been 
plainly shown by Romanes. In the case of the Australian 
aborigines, which has it been? According to the “Law” of 
Delboeuf, quoted by ines a constant cause of variation, 
however insignific ant it may be, changes the uniformity of 
type little by little, and er der it ad infinitum. From 
geneous, the homogeneity will be invaded at a single point, 
differentiation will penetrate the whole, and, after a time— 
it may be an infinite time—the differentiation will have dis- 
integrated it altogether. Has this differentiation which 
existed amongst Australian aborigines ane accentuate fe 
diffused by heredity? Prof. Pearson and colleagues, wri 
ing on “Genetic ibo eme a Selection” in deem Philosophi. 
cal Transactions of the Royal ety of London, vol. 192, in 
their concluding nau ma e the ollowing statement :— 
There is, so to speak, in every species an innate tendency to 
progressive change, quantitatively tnsatareible by determin- 
ing the correlation co-efficients between fertility and Er 
characteristics and between u} in the parents and 
offspring. This “innate tendency" is no mysterious tors 
causing evolution to take cma in a pre-ordained direction, 
it is si cal organization of the indivi- 
race to is types, as e Bhd supporters of panmixia suggest, 
or the — of the imd t 
iri selection must not be looked upon. as ar an 
otherwise permanent or stable type; 
checking, guiding, and otherwise controlling a progressive ten- 
dency to change. 
Heredity, in the presence of free intercrossing, cancels the 
tendency to variability, causing fixity of type. A considera- 
