4 INTRODUCTION 



subject, it seemed inadvisable to stop at the animals, and therefore, 

 having some bowing acquaintance with the floras of Britain, North 

 America and Australia, in addition to that of New Zealand, in due 

 course I added the introduced plants to my previous lists. The two 

 groups can hardly be separated in this connection, and on account of 

 their inter-relations it is best to study them together. 



This work does not purport to be merely a list of naturalised 

 animals and plants. I have recorded the introduction of a great 

 number of species which have not succeeded in establishing them- 

 selves, though in some cases repeated attempts were made to naturalise 

 them. The reasons for these failures are often so obscure that no 

 plausible explanation has yet been given. For example the greenfinch 

 and the chaffinch have thriven remarkably, the allied linnet has quite 

 failed. Among fishes, the Pacific-coast Salmon (Onchorhynchus 

 Quinnat) has become strongly established on the east coast of the 

 South Island; while all attempts to naturalise the Atlantic Salmon 

 (Salmo solar), though carried on unceasingly for half a century and 

 in half a hundred different streams, have absolutely failed. The dif- 

 ferent attempts made are recorded under the various species, and 

 such reasons as can be suggested for failure are also recorded. It 

 seems to me that the failure of a species to become established in 

 a new country into which it has been introduced, under what appear 

 to be most favourable conditions, is as important a biological problem 

 as the success of another species, and that the causes of the failure 

 are worthy of examination. 



In order that the various species referred to in this work might 

 be recognised with a minimum possibility of mistake, I found it 

 necessary to adopt some authoritative and readily-accessible scheme 

 of classification and nomenclature. It was impossible to go into all 

 the niceties (or obscurities) of zoological and botanical nomenclature ; 

 all that appeared to be essential was that the species referred to should 

 be readily recognisable. Accordingly for the introduced animals I 

 adopted, as far as possible, the schemes used by the various authors 

 of the Cambridge Natural History (Macmillan & Co., London, 1895- 

 1909); and for the plants the Manual of the New Zealand Flora by 

 Mr T. F. Cheeseman (Wellington, 1906). 



A considerable, indeed the major portion of this work is necessarily 

 a compilation, but the information has been secured only by a laborious 

 examination of all the available literature on the subject, and by 

 very extensive correspondence. There is no doubt a great deal of 

 information buried in the columns of the daily press of old days, 

 which I have not been able to consult except in isolated instances. 

 An immense amount of sifting of the wheat from the chaff has also 



