TRANSACTIONS OF SECTION D. 195 



The causes which lead, to the estabhshment of certain 

 forms and the non- estabhshment of others, the changes 

 brought about on ah'eady-existing forms by these new intro- 

 ductions, and the changes which they themselves undergo 

 under the altered conditions, constitute one of the most com- 

 plicated problems which offer themselves for solution to the 

 naturalist in New Zealand. The questions which arise overlap 

 one another at every turn, and it is a somewhat difficult task 

 to attempt in a brief address to grasp their main features and 

 present them in a clear manner. 



In endeavouring to point out a few of the interesting 

 questions which have suggested themselves to me in this con- 

 nection, I must premise by stating that my own observations 

 have been mainly confined to the southern portion of the South 

 Island. Some of my statements, therefore, which may be 

 strictly accurate as applicable to that limited area, may be 

 found to require modification or alteration as regards other 

 parts of the colony. Stretching as these Islands do between 

 the Sdth and 48th parallels of south latitude, it is evident that 

 the range of climate is very great. In the northern portion of 

 the North Island the climate is w^arm-temperate, so that the 

 plants and animals of the Mediterranean region of Europe 

 thrive there : in the south of the South Island, on the other 

 hand, we find ourselves in a second Scotland, with severe 

 winter frosts, which indeed prevail throughout the interior and 

 eastern portions of this Island. 



The humidity also of the Islands is very different in different 

 parts. To take this Island alone : we find that the rainfall on 

 the west coast is very heavy, the saturated winds, in being 

 forced over the Southern Alps', parting with a very large por- 

 tion of their moisture, and pouring it down on the coast ranges. 

 Probably in no part between Cape Foulwind and Preserva- 

 tion Inlet is the annual rainfall less than lOOin., while 

 there is reason to believe that in many localities it may rise 

 even to 300in. On the eastern portions of the Island, 

 especially where intermediate ranges like the Kakanuis iu 

 Otago and the Kaikouras in Marlborough still further inter- 

 cept the rain-carrying clouds, the annual precipitation falls to 

 30in. and less. 



(a.) Suitability op New Zealand as a Field for 

 Naturalisation. 

 New Zealand has always been recognised by naturalists as 

 a distinct zoological and botanical province, one of surpassing 

 interest on account of the long isolation it has undergone, and 

 in consequence of the unique character of its fauna, and, in a 

 less degree, of its flora. It has been colonised by Europeans 

 at an age when questions of scientific interest were beginning 



