INTRODUCTORY ESSAY. i i 



In conclusion, if I may venture to assume a limit to the Flora of New Zealand, from the data 

 at my disposal, and from a comparison of these with those of better investigated countries with which 

 I am familiar, I should regard 4000 as the probable approximation ; of which 1000 may be flowering 

 plants. Compared with any other countries in the same latitude, this is a very scanty Flora indeed, 

 especially as regards flowering plants ; of which Britain contains, in about the same area, upwards <A 

 1400 species ; and in Tasmania, not yet well explored, and only containing one-third of the area, 

 upwards of 1000 have already been discovered. In Cryptogamic plants, on the other hand, these 

 islands are extremely rich ; not only proportionately to the Phsenogamic, but absolutely so. Great 

 Britain, where these lower Orders have been assiduously studied for fifty years, contains about fifty 

 Ferns, and Tasmania sixty-four. 



In the above remarks I have not alluded to the Floras of some outlying islands, all of which 

 have more or less claim to be considered botanically as a part of New Zealand. Of these, the extent 

 of its Flora renders Norfolk Island the most important : it contains many more tropical forms than 

 New Zealand, and is also more closely connected with the Pacific and Australian Floras. Chatham 

 Island* has been visited by Dr. Dieffenbach, who brought thence a very few plants, all identical with 

 or closely allied to New Zealand species. Lord Auckland's Group and Campbell's Island were 

 investigated by myself in the Antarctic Expedition, and also by the French and American Antarctic 

 Expeditions, under Admiral D'Urville and Commodore Wilkes. All the known species have been 

 published in the first- volume of the 'Antarctic Flora;' they are almost all identical with or closely 

 allied to New Zealand plants, and amongst them are found a few Antarctic American ones, not 

 hitherto discovered in New Zealand. They include 370 species, of which 100 are flowering plants. 

 and of these again 54 are known natives of New Zealand. As however neither these islands, nor 

 the mountains of the Middle Island of New Zealand, have been explored satisfactorily, it is probable 

 that a much larger proportion of their flora is common to both. 



CHAPTER II. 



ON THE LIMITS OF SPECIES; THEIR DISPERSION AND VARIATION. 



It is no part of my present object to discuss the theoretical views that have been entertained on these 

 obscure subjects : my aim is to draw attention to a few leading questions of great practical importance, 

 which ought not to be overlooked, even if they do not force themselves on the notice of natu- 

 ralists. In explanation of my meaning I shall assume certain positions-)-, and adopt them as principles 



* A few Chatham Island plants were engraved in Paris many years ago for a magnificent work, ' Voyage de 

 la Venus ;' but the letterpress of that publication has never appeared, nor has the Botany of that voyage been 

 completed. 



f I need hardly remark that these have no claim to originality ; they are merely selected as heads of the subjects 

 upon which I intend to enlarge. 



