Plants in their Relation to Others. 499 
genus in the flora that had more than one species, and a planning of the 
areas occupied by the different species resulted in giving for all the larger 
genera such maps as that for Ranunculus here reproduced, which shows 
clearly the massing of the species near the middle of the South Island. 
Examination of all the genera showed that these maxima occurred, not 
casually all over New Zealand, but in masses, especially at the far north, at 
the centre, and at the point where they show in Ranunculus, rather to the 
south of the middle of the South Island. Upon these results I have based 
my contention that the flora of New Zealand has been the result (24, p. 475 ) 
of four separate invasions — one from Indo-Malaya direct (northern invasion, 
reaching New Zealand at the far north, and when added together givingthe 
Endemics 
Wides 
-100 -200 -300 -400 - 500 - 600 - 700 -800 - 900 -1000 -1080 
Diagram 4. Northern invasion : vertical figures are numbers of species, horizontal the 
distances in miles from North Cape of New Zealand. 
curves in Diagram 4 , which shows the numbers of wides and endemics 
at each successive zone of one ‘hundred miles, working south), one from 
Polynesia by way of the Kermadec Islands, one from Australia (western or 
central invasion), and one from the south (southern invasion, curves given in 
Diagram 5 , with maxima 1 at 800-900 miles south of the North Cape, 
i. e. rather south of the middle of the South Island. 
Results were now flowing in so easily and naturally that I became 
a firm believer in the truth of my hypothesis, and applied it to predictions 
of what would or would not be found in certain places or under certain 
conditions. Some of these predictions were simple tests, as when I predicted 
(21, p. 27 ) nearly half the species that would be found upon Stewart Island 
from a knowledge of the flora of New Zealand, or all but fourteen of those 
1 The double curve given for wides is explained thus : a few species of some of the genera are 
evidently northern, and die out as one goes south. The upper curve includes these, the lower and 
more correct curve excludes them. The narrowing distance between the curves shows the way in 
which they die out to the south. 
