200 KEPOET— 1891. 



colony along with the plants on which they feed. It will be 

 interesting to watch whether these pests spread to indigenous 

 plants. I have appended a list of introduced insects which Mr. 

 G. V. Hudson, of Wellington, has kindly furnished me with, 

 but which he states is incomplete. 



(c.) Examples of Successful Naturalisation. 



When we come to consider in detail the numerous forms 

 introduced by societies and individuals with the express purpose 

 of naturalising them in the colony we find that most attention 

 has been devoted, as indeed might have been expected, to 

 animal immigration. 



Among successful cases of naturalisation we must give the 

 palm to the rabbit. No one will be found ready to accept the 

 responsibility of having introduced the rabbit ; yet various 

 acclimatisation societies, and several private individuals, 

 brought these animals into the colony on their own account, 

 and liberated them at various parts. It is no part of my 

 purpose hei'e to describe the history of the introduction of 

 these animals : my object is to show how they have developed 

 since their liberation. It may be said that they found here 

 no natural enemies, for, though hawks, wekas, and wild cats 

 attacked and destroyed a few young ones, yet the average 

 increase has been prodigious, and natural selection has hardly 

 begun to affect the stock. With a plentiful supply of food, a 

 favourable climate, and absence of enemies, the rabbits would 

 soon have increased to such an extent that all other herbi- 

 vorous animals would have been exterminated, and then 

 would have ensued a struggle for existence among themselves, 

 which would have resulted in the production of a naturally- 

 selected breed, whose characters, however, it is impossible to 

 predict. Of course such a state has never been reached in 

 these Islands ; but it has been approached in certain localities, 

 and, wherever the rodents have increased, means to destroy 

 them have had to be resorted to. The most potent of these is 

 phosphorus, and it is interesting to note that, as no rabbits can 

 escape its poisonous action unless by abstaining from eating 

 the poisoned oats, so the wholesale destruction which it causes 

 cannot in any way affect the developement of the species except 

 in so far as it reduces the number of individuals, and so does 

 away with competition. To obviate the evil effects caused by 

 the increase of the rabbits, various species of Mustelidse (ferrets, 

 weasels, and stoats) have been introduced, and these are them- 

 selves proving such a pest that the last state of this country 

 promises to be worse than the first. Cats, which have been 

 frequently turned out in numbers, keep down young rabbits, 

 rats, mice, and, to a certain extent, small birds ; but ferrets and 

 weasels, leaving the rabbits alone, are now exterminating not 



