xu FLORA OF NEW ZEALAND. 



cases the species is the same, and the parent individuals were not even varieties of one another, 

 except so far as regards hardiness j in other words, the specific character remains unaltered in spite 

 of the change of constitution, just as the climate of one part of the globe disagrees with the human 

 race of another, and is even fatal to it. 



Such are a few of the leading phenomena or facts that appear to me to give the greatest weight 

 to the opinion that individuals of a species are all derived from one parent : for such arguments as 

 the New Zealand Flora furnishes, I must refer my readers to the following chapter. I would again 

 remind the student that the hasty adoption of any of these theories is not advisable : plants should 

 be largely collected, and studied both in the living and dried states, and the result of their dissection 

 noted, without reference to any speculations, which are too apt to lead the inquirer away from the 

 rigorous investigation of details, from which alone truth can be elicited. When however the oppor- 

 tunity or necessity arises for combining results, and presenting them in that systematic form which 

 can alone render them available for the purposes of science, it becomes necessary for the generalizer 

 to proceed upon some determinate principle ; and I cannot conclude this part of the subject better 

 than by adopting the words of the most able of Transatlantic botanists, who is no less sound as a 

 generalizer than profound in his knowledge of details : — " All classification and system in Natural 

 History rests upon the fundamental idea of the original creation of certain forms, which have natu- 

 rally been perpetuated unchanged, or with such changes only as we may conceive or prove to have 

 arisen from varying physical influences, accidental circumstances, or from cultivation*." 



§2. 



Species vary in a state of nature more than is usually supposed. 

 The news entertained as to the limitation of species appeal 1 to be quite arbitrary : no general 

 principles have been discovered for the guidance of the systematist ; and those that are adopted vary , 

 in kind and in value with every natural group. It is not therefore surprising that two naturalists, 

 taking opposite news of the value of characters, should so treat a variable genus that their conclu- 

 sions as to the limits of its species should be wholly irreconcilable. Some naturalists consider 

 every minute character, if only tolerably constant or even prevalent, as of specific value; they 

 consider two or more doubtful species to be distinct till they are proved to be one ; they limit the 

 ranges of distribution, and regard plants from widely severed localities as almost necessarily distinct ; 

 they do not allow for the effects of local peculiarities in temperature, humidity, soil, or exposure, ex- 

 cept they can absolutely trace the cause to the effect ; and they hence? attach great importance to 

 habit, stature, colour, hairiness, period of flowering, etc. These views, whether acknowledged or not, 

 are practically carried out in many of the local floras of Europe, and by some of the most acute and 

 observant botanists of the day ; and it is difficult to over-estimate the amount of synonymy and confu- 

 sion which they have introduced into the nomenclature of some of the commonest and most variable of 

 plants. In such hands the New Zealand genera Coprosma, Cehnisia, Epilobium, etc., may be indefi- 

 nitely extended. The principles I have adopted are opposed to these : I have based my conclusions 



species from 10,000 are tender. The common scarlet Rhododendron of Nepal and the North-west Himalaya is 

 tender, but seedlings of the same species from Sikkim, whose parents grew at a greater elevation, have proved 

 perfectly hardy. 



* Botanical Text-book, p. 303, bj Professor Asa Gray, of Cambridge University, U.S. 



