EUROPEAN OCCUPATION 519 



when discovered. It must formerly have occurred over a considerable 

 portion of the New Zealand area, for its relationships are more with 

 those of the Australian species of Cynoglossum than with Myosotis, 

 which is still well represented in this country. 



Gastrodia Cunninghamii, Hook. f. This orchid has large thick 

 tuberous roots which contain erythro-dextrin in place of starch. These 

 are eaten greedily by pigs and by both common species of rats 

 (M. rattus and M. decumanus). Kirk remarks that it 



has become very rare in districts where the black rat is plentiful. On one 

 occasion, in 1874, I found three remarkably fine specimens, quite two 

 feet in height, with tubers 6 in. or 7 in. in length, and placed them in 

 what seemed a safe place in a hut at Omaha, but during the night they were 

 carried off by the rodents. 



I have noticed this disappearance of this species from the neigh- 

 bourhood of Dunedin, where it used to be common during the last 

 thirty years, but am more inclined to put it down to another cause 

 than the fondness of rats for its roots. It is commonly given as a 

 character of this genus that its roots are usually parasitic on the roots 

 of other plants. My own observations would tend to make me ques- 

 tion the accuracy of this statement, at least I have never been able 

 to verify it. A great number of bush plants appear to be dependent 

 on symbiotic fungi for their nourishment, and this, I am inclined to 

 think is one of them. It certainly will not grow on any garden soil, 

 but the same difficulty is experienced with other bush plants which 

 are not root parasites. I should term it a saprophyte. 



Marattia fraxinea, Smith. This fine fern is also fast disappearing. 

 Cheeseman says: "The large starchy rhizome was formerly eaten by 

 the Maoris, and hence the plant was occasionally cultivated near 

 their villages." Aston blames the pigs for eating it out, as they are 

 also very fond of the rhizomes. 



Local destruction of the native flora is quite a different matter 

 from extermination, and frequently is not due so much to introduced 

 animals as to the direct action of man. Thus by bush clearing, surface 

 burning, draining, and breaking up the surface for cultivation, im- 

 mense areas have had their native vegetation nearly quite destroyed, 

 and introduced animals have assisted in this work. 



A remarkable example of this is to be seen in Central Otago where 

 an area of many thousands of acres of what was once good grazing 

 land, covered with heavy tussock grasses, has had its surface nearly 

 denuded of vegetation and has been reduced to the condition of a 

 desert. In this area the three active agencies in desiccating the country 

 have been fire, overstocking with sheep, and rabbits. By enclosing 

 areas with rabbit-proof fences, and keeping grass-feeding animals 



