New Zealand Flora , zvith a Reply to Criticism. 361 
as Coromandel, P. distichuni as far as Waikato River, all at distances not 
over 430 miles from North Cape. It is clear that these are northern types, 
and that some of these families invaded New Zealand at both ends. If we 
subtract them, we get for the wides the result: 
83 
21 
87 
21 
100 
23 
97 
17 
IOL 
1 7 
105 
14 
104 
11 
102 
8 
100 
3 
9 i 
5 i 
62 
66 
77 
80 
84 
9 1 
93 
94 
97 
9 i 
5 i 
a result which brings the wides exactly into line with the endemics, and 
with the maximum at the same zone (see lower of two curves for wides). 
Many will perhaps object to my treatment of these families, and say 
that if one pick out the families with a maximum at a certain point, and 
add them up, it is not surprising if they show great regularity in the curve. 
True, but the surprising thing has already been pointed out ( 19 , p. 444), in 
giving these curves for the individual families, that all of them show such 
curves, and similar curves, rising to a maximum and then falling off again— 
a result quite unsuspected until I had applied to the New Zealand flora the 
ideas suggested by age and area, and had added up for each zone the actual 
plants that occurred therein. 
It seems probable that these families, or a great part of them, which 
show as great symmetry in their curves as did the northern families, arrived 
in New Zealand by a southern route, which perhaps reached New Zealand 
with its central part about the middle of the southern half of the South 
Island. The maxima are at 800-900 miles, or a little north of Dunedin, 
which lies on the 900-mile line. Whence this southern bridge came is 
a more complex question that must be left for the present unanswered. 
Passing on now to deal with the constitutional habit of these plants, the 
first thing that one notices is that not only are they much more numerous 
(though of fewer families) than the northern invasion, but they are nearly all 
herbs, there being only 83 shrubs and no trees in 499 species. Of the 
shrubs 67 are Veronicas. The proportion of herbs is 83 per cent, almost 
exactly equal to the percentage of trees and shrubs in the northern families 
that we first dealt with. Now as these herbs are mostly types of the 
Northern Hemisphere, it is clear that herbs must be very ancient, but as to 
whether they are older or younger than the trees and shrubs, the flora of 
New Zealand gives little clue. On the whole, one imagines, these southern 
types perhaps arrived in New Zealand later than the northern, for they do 
take some notice of Cook’s Strait, quite a number being held up there, and 
they take about as much notice of Foveaux Strait as the northern forms, 
though they must have started so much nearer to it. Their curve of zoning 
of endemics, also, is rather more sharp, which would tend to show that the 
endemics were younger than the northern endemics. But it is clear that 
New Zealand alone will not permit of drawing any conclusion with the 
aid of age and area as to the relative ages of the different habits of growth. 
