270 EVOLUTION AND THE PRESENT AGE 
It is now understood that one of the principal factors 
in establishing a high degree of vitality has been com- 
petition for the means of supporting life. In the great 
continental mass of Europe, Asia, and Africa the 
forms of life have been most numerous and the com- 
petition has been keenest; hence life, both animal and 
vegetable, has been more strongly developed than else- 
where; creatures have been produced that are tougher 
and more resourceful than in other places; they have 
the peculiar combinations of qualities that enable their 
possessors to live more highly developed. Second in 
this respect comes North America; then, very far 
below it, because more isolated, comes South America; 
lowest of all, because most isolated, comes Australasia. 
Australian man is the lowest of the human species, 
not having risen to the bow-and-arrow stage; the 
Maori of New Zealand, a high type of barbarian, is not 
indigenous, but a comparatively late arrival; in its 
natural history generally Australasia has only reached 
a point attained in the northern hemisphere two or 
three geological periods ago. In the chalk period mar- 
supials abounded in Europe, but they were long ago 
extinguished by placental mammals of greater vitality, 
and the same thing is now happening in Australasia. 
The true reason for the resemblance between any 
fauna and its predecessors in the same area is that 
the later forms are the slightly modified descendants 
of the earlier forms. Thus there arose the suspicion 
that the millions of separate acts of creation once 
thought necessary to account for the specific forms of 
plants and animals were as unnecessary and improb- 
able as the series of convulsions formerly imagined as 
the causes of geological change. What could those 
