126 



Transactions. 



Table II, 



V. Introduced Animals and Plants. 



The effect of animals and plants introduced intentionally and acci- 

 dentally tlirougli the agency of man is most marked on the vegetation of 

 Sunday and Macauley Islands. It amounts to an alteration of the forest 

 formation on Sunday Island ; and the occifpation of ground cleared of forest 

 or scrub, by meadow formations on both Sunday and Macauley Islands. During 

 the early part of last century Sunday Island was the headquarters of an 

 extensive whaling industry carried on in the south-western Pacific. In 

 order to afford means of suhsistence for possible castaways the whalers 

 liberated goats on Sunday and Macauley Islands, and, to provide the goats 

 with pasture on Macauley Island, burnt the scrub so that grass might grow. 

 The goats increased rapidly in their new home, and did not suffer from the 

 lack of water on the islands, as these animals are satisfied with the moisture 

 taken with the herbage. On Macauley Island they effectually prevented 

 the regrowth of scrub, so that now in all 'places accessible to them no more 

 vegetation is to be found than a close-cropped beard-grass (Polypogon mons- 

 peliensis) meadotv. 



On Sunday Island, as their numbers increased the goats spread to all 

 parts, and, being expert cliff-climbers, little vegetation was beyond their 

 reach. They wander about through the forest in herds of twenty or more, 

 and eat a wonderful variety of vegetable substances — bark and leaves of 

 trees, seedlings, and ferns — thus thinning the undergrowth considerably. 



Certain plants once common have been almost exterminated by them, 

 and are now found only on cliffs and other inaccessible places. Conspicuous 

 examples are Homolantlius polyandrus, Veronica breviracemosa, Aspleniwn 

 lucidum, and A. Shuttle worthianum. 



The seedlings of other species are seldom allowed to grow up, and hence 

 only such plants as begin their existence on Cyathea trunks, and, growing 

 downwards and often strangling their host, take root in the ground, are 

 able to reach maturity. This commonly happens with Nothopanax arboreum, 

 which promises to become very rare or even extinct on Sunday Island ; 

 and often with Metrosideros villosa. 



Young plants of Cyathea, kermadecensis are greedily eaten, and, though 

 mature plants of this magnificent fern are plentiful, young ones are ex- 

 tremely rare. 



With Rhopalostylis Baueri a fair number of the seedlings grow up, as 

 goats merely browse on the young palms, which are everywhere abundant. 



The bark is stripped from the trunks of Pisonia Brunoniana and Notho- 

 panax arboreum as far as goa^s cr.n reach. This operation, however, kills 



