347 
New Zealand Flora , with a Reply to Criticism . 
To turn now to the principal points in Dr. Sinnott’s criticisms, as given 
above, the first is that age and area is an assumption. Perfectly true, but 
so is Natural Selection, and it is no more improbable that area occupied 
should increase with age than that a well-equipped plant A should beat 
a less well-equipped B in the struggle for existence. Both seem fairly self- 
evident truths. But for the last fifty years Natural Selection, to the practical 
exclusion of everything else, has been regarded as the chief operative factor 
in evolution and geographical distribution. We are still, however, without 
any proof that it determines the area occupied by species, whereas actual 
arithmetical results of the clearest kind, which are rapidly accumulating, 
