CoLEis'so. — Botany of the ITortli Idaml of New Zealand. 235 



specific distinctions really such ? Has a species a power of evolution and 

 metamorpliosis per se ; wMcli, the factors, time, suitable soils, and climate 

 being given, knows no bounds ? Have there been in past aeras any potent 

 occult elemental causes at work, differing only in intensity, combination, and 

 constancy from what now are, through which sub-varieties, varieties and 

 species were the more readily evolved ? May not a plant be outwardly 

 distinct, yet chemically the same ? May a plant be almost entirely outwardly 

 the same with another, and yet chemically distinct ? May not nature educe, 

 under the most favourable circumstances, from two genera slightly differing, 

 fertile plants forming new genera more divergent ? and may not such (again 

 crossed by nature) produce plants still more widely differing ? Why, 

 among several species of any given endemic genus (e.y. Coprosma, Dracophyl- 

 lum, Veronica^, should some species be of robust and vigorous growth and 

 development, and common everywhere ; other species of weakly growth and 

 development, and comparatively scarce ? Are some of these forms older than 

 others ? and if so, which are' the seniors ? Are not the more robust and 

 vigorous ones, through their own progressive increase, likely to extirpate 



the weaker ones ? Such are some of the thoughts which 



must often arise in the intelligent botanist's mind, especially when contem- 

 plating new or old forms in far off insular situations. 



II. GrEOGEAPHIC. 



3. But laying aside the ideal and theoretical, and coming to the practical 

 and real, how does the vegetation of this Northern Island of New Zealand 

 appear when seen for the first time ? What is its peculiar aspect ? The 

 answer will mainly depend on two things : first, the place whence the newly- 

 arrived beholder last came ; and second, the place in New Zealand where he 

 lands ; not forgetting his expectations — as the eye ever sees what the mind 

 brings. If he last left the shores of Grreat Britain, then the recollection of 

 her verdant fields may cause the brown fern-clad hills and dark-green forests 

 of New Zealand to appear the more gloomy and sad ; if his last landscapes 

 were either South African or Australian, then their glaucous sea-green hue 

 and arid appearance Avill be agreeably contrasted with New Zealand forest 

 vegetation ; but if he should have come hither direct from the sunny skies 

 and islands of the tropics, with their graceful perennial light ever-green 

 dress, then the New Zealand hills and dells may appear very sombre, and 

 will suffer from recollection and comparison. Again, if he should happen to 

 anchor in one of the many rivers or harbours north of the Thames, while 

 the ubiquitous brown fern (Pteris esculenta) is everywhere, he will be 

 struck with the appearance of the white mangrove (Avicennia officinalis) 

 growing within the range of the tide, and the romantic pohutukawa {Metro- 



