474 
ISLAND LIFE. 
PART. II. 
and abundant seeds must be dispersed by tlie wind almost as 
readily as the spores of ferns. 
Another specialised group — the Scrophularinese, abounds in 
New Zealand, where there are six:ty-two species ; but though 
almost all the genera are Australian only three species are so. 
Here, too, the seeds are usually very small, and the powers of 
dispersal great, as shown by several European genera — Vero- 
nica , Euphrasia, and Limosella, being found in the southern 
hemisphere. 
Looking at the whole series of these Australo-New Zealand 
plants, we find the most highly specialised groups — Composite, 
Scrophularinese, Orchidese — with a small proportion of identical 
species (one-thirteenth to one-twentieth), the less highly special- 
ised — Banunculacese, Onagrarise and Ericese — with a higher 
proportion (one-ninth to one-sixth), and the least specialised — 
Junceae, Cyperaceae and Gramineae — with the high proportion in 
each case of one-fourth. These nine are the most important New 
Zealand orders which contain species common to that country 
and Australia and confined to them ; and the marked corre- 
spondence they show between high specialisation and w r ant of 
specific identity, while the generic identity is in all cases ajrprox- 
imately equal, points to the conclusion that the means of 
diffusion are, in almost all plants ample, when long periods of 
time are concerned, and that diversities in this respect are not 
so important in determining the peculiar character of a derived 
flora, as adaptability to varied conditions, great powers of multi- 
plication, and inherent vigour of constitution. This point will 
have to be more fully discussed in treating of the origin of the 
Antarctic and north temperate members of the New Zealand 
flora. 
Summary and Conclusion on the New Zealand Flora. — Confining 
ourselves strictly to the direct relations between the plants of. 
New Zealand and of Australia, as I have done in the preceding 
discussion, I think I may claim to have shown, that the union 
between the two countries in the latter part of the Secondary 
epoch at a time when Eastern Australia was widely separated 
from Western Australia (as shown by its geological formation 
and by the contour of the sea-bottom) does sufficiently account 
