EUROPEAN OCCUPATION 525 



lawns. It cuts the grass at the roots, and in this manner destroys 

 the plants, so that the surface growth dies right out. The larvae are 

 sufficiently deep in the soil to be beyond the range of starlings and 

 other insectivorous birds, and the chief means of destruction are 

 either flooding the land, or rolling with a very heavy roller. 



Two indigenous scale insects have been recorded as attacking 

 introduced plants. In the Agricultural Department's Report for 1909, 

 Diaspis santali, Maskell, is reported as becoming troublesome in 

 orchards, where it attacks the plum trees; while Dactylopitis aurila- 

 natus, Maskell, has established itself on Norfolk Island Pines and 

 other species of Araucaria in the North Island. 



Though these few are the only examples recorded of indigenous 

 species of insects attacking introduced plants, it must be noted that 

 the small number is probably due to the fact that observations on the 

 point have not been made. Anyone taking up a research on this 

 subject would find that the list might be multiplied to a very great 

 extent. 



Inter-relation of Native and Introduced Flora 



The introduction of foreign plants into New Zealand has wrought 

 a very radical change in the facies of the vegetation. The distinctive 

 character of the native flora has disappeared from nearly all closely 

 settled portions of the country, and what may be called a cosmopolitan 

 type of vegetation has taken the room formerly occupied by the dis- 

 placed species. This fact led many naturalists to the conclusion that 

 the indigenous fauna was doomed to destruction, and would in time 

 be exterminated by the alien introductions. Sir J. D. Hooker, who 

 visited New Zealand in 1841, and published an account of its plant 

 life in the Flora Novce-Zealandice, which forms the second part of 

 the Botany of the Antarctic Expedition of Sir J. Ross, published in 

 1854-5, was the first who voiced this conclusion, and the pre-eminent 

 position he occupied as the leading British botanist, deservedly and 

 naturally caused his views to be widely accepted. He came to the 

 conclusion that the northern or Arctic element in all the south 

 temperate floras, including that of New Zealand, was due to the 

 wonderful aggressive and colonising power of what he termed "the 

 Scandinavian Flora." He says : 



When I take a comprehensive view of the vegetation of the Old World, 

 I am struck with the appearance it presents of there being a continuous 

 current of vegetation (if I may so fancifully express myself) from Scandi- 

 navia to Tasmania Scandinavian genera, and even species, reappear 



everywhere from Lapland and Iceland to the tops of the Tasmanian Alps 

 in rapidly diminishing numbers it is true, but in vigorous development 



