CHAP. XXII.] 



THE FLORA OF NEW ZEALAND. 



469 



to the great western island, along with the peculiar Acacias and 

 Eucalypti, which at a later period spread over the whole con- 

 tinent. It is equally accordant with the view we are maintain- 

 ing, that among the groups which Sir Joseph Hooker enumerates 

 as " keeping up the features of extra tropical Australia in its 

 tropical quarter," several should have reached New Zealand, 

 such as Drosera, some Pittosporess and Myoporinese, with a few 

 Proteacese, Loganiacese, and Restiacese ; for most of these are not 

 only found in tropical Australia, but also in the Malayan and 

 Pacific islands. 



Tropical character of the JSfciv Zealand Flora, explained. — In 

 this origin of the New Zealand fauna by a north-western route 

 from North-eastern Australia, we find also an explanation of the 

 remarkable number of tropical groups of plants found there : 

 for though, as Sir Joseph Hooker has shown, a moist and uni- 

 form climate favours the extension of tropical forms in the 

 temperate zone, yet some means must be afforded them for 

 reaching a temperate island. On carefully going through the 

 Handbook^ and comparing its indications with those of Bentham's 

 Flora Australiensis, 1 find that there are in New Zealand thirty- 

 eight thoroughly tropical genera, thirty-three of which are found 

 in Australia — mostly in the tropical portion of it, though a few 

 are temperate, and these may have reached it through New 

 Zealand.^ To these we must add thirty-two more genera, which, 



1 The following are the tropical genera common to New Zealand and 

 Australia : — • 



1. Melicope. Queensland, Pacific Islands. 



2. Eugenia. Tropical Australia, Asia, and America. 



3. Passiflora. Queensland, Tropics of Old World and America. 



4. Myrsine. Tropical and Temperate Australia, Tropical and Sub-tropical 



regions. 



5. Sapoia. Australia, Norfolk Islands, Tropics. 



6. Cyathodes. Australia and Pacific Islands. 



7. Parsonsia. Tropical Australia and Asia. 



8. Geniostoma. Queensland, Polynesia, Asia. 



9. Mitrasacme. Tropical and Temperate Australia, India. 



10. Ipomcea. Tropical Australia, Tropics. 



11. Mazus. Temperate Australia, India, China. 



12. Vifex. Tropical Australia, Tropical and Sub-tropical. 



13. Pisonia. Tropical Australia, Tropical and Sub-tropical. 



