G. M. Thomson. — On the Origin of the New Zealand Flora. 485 



Art. LXXVII. — On the Origin of the Neiv Zealand Flora — being a Presi- 

 dential Address to the Otago Institute. By Geo. M. Thomson, F.L.S. 

 [Read before the Otago Institute, 31st January, 1881.] 

 Among the many questions of interest which offer themselves for sokition 

 to the botanist, none possess more fascination than those deahng with the 

 geographical distribution of plants ; and if this is so in other parts of the 

 world it is doubly so in New Zealand, where the existing conditions are 

 almost unique. The present distribution of our flora leads up to a wider 

 and far more interesting question, viz., its origin, and the investigation of 

 this brings under review many collateral subjects, among which may be 

 considered the former land connections existing between what is now New 

 Zealand and other parts of the world. 



The main question cannot be considered alone, but must be taken in 

 conjunction with the origin and distribution of our fauna, and with the great 

 geological changes which have been effected in past times, and which have 

 brought about in our time a distribution of land and water very different 

 from that which existed at the end of the Secondary or commencement of 

 the Tertiary period. 



But it would be almost impossible in the limits of a single address to 

 discuss the subject in all its aspects, and I shall therefore confine myself to 

 a small portion only of it, stating in the first place what has been written 

 on this topic, and then pointing out some of the interesting facts which an 

 examination of it reveals. 



Every naturalist who has visited New Zealand has had his attention 

 drawn to the many remarkable features of its fauna and flora, but Sir Joseph 

 Hooker, Professor F. W. Hutton, and Mr. Wallace, are the only writers 

 whose works I am acquainted with, who have attempted to solve the prob- 

 lems presented to them. 



The first-named botanist in the introduction to the "Flora Novse- 

 Zealandiffi" has summarized the information at his disposal in a masterly 

 essay, which forms the basis of our knowledge as to the distribution of the 

 Flora. But he has not sought to trace the origin of our species more 

 directly, confining himself to their affinities and to their occurrence in 

 other countries, but not seeking to solve the question as to how they have 

 found their way here. Between the publication of the " Flora Nov^- 

 Zealandise" (in 1853) and the issue of the " Handbook" (in 1867), about 200 

 species of flowering plants were added to the Flora, while up to date about 

 150 more species have been added, bringing the total up to 1,085 species. 

 More close and accurate investigations of many of our local botanists are 



