292 Transactions. — Botany. 



forest as a distinct plant-formation. As a proof of this we 

 find the two trees which give the distinctive character to this 

 forest, Senecio huntii and Dracophyltum arboreum, occurring 

 in lowland swamps and in swampy forests, but they are al- 

 most absent from the drier ground. It is true that other 

 Chatham Island trees also grow in swamps (see " Swamp For- 

 mation "), but they most likely are merely the plants of a line 

 of tension between forest and swamp, and would be readily 

 eradicated by trees better adapted for wet surroundings. 

 Thus, Olearia traversii, Coronocarpus Icevigata, and Bhapalo- 

 stylis baueri are absent from the tableland forest ; Hy- 

 menanthera chathamica is rare ; and, with the exception of 

 Veronica giganteu, the other trees of the lowland forest are 

 much inferior in numbers to the two above-mentioned domi- 

 nant species. The largest forest on Chatham Island be- 

 longs to this formation. It occupies the whole of the 

 south-west corner of the island, extending north -wards 

 to a line connecting Tuku and Pipitarawai. All the gul- 

 lies of the tableland are also filled with this class of forest; 

 and in some cases, these gullies becoming deep as they ap- 

 proach the sea, their forests are of considerable size. In most 

 other cases the trees of the tableland gullies form merely 

 patches or long lines. The most abundant tree of the forma- 

 tion under consideration is Dracophyllum arboreum ; next 

 comes Senecio huntii, which, besides occurring in the interior 

 of the forest as a regular constituent, forms the outermost row 

 of trees, almost to the exclusion of all others, near the line 

 of tension between forest and bog. Such a line of Senecio 

 huntii is a magnificent spectacle when the trees are covered 

 with their masses of yellow blossoms. Veronica gigantea occurs 

 also very abundantly, while the remaining forest trees, Co- 

 prosma chathamica, Myrsine chathamica, Pscudopanax chat- 

 hamica, and Corokia macrocarpa, are found in smaller but 

 still very considerable numbers. These seven trees do not by 

 any means always occur in the proportion just stated; indeed, 

 almost any one of them may become of more importance in 

 the small patches of forest. The central portion of the large 

 forest mentioned above has only quite recently been disturbed, 

 a sheep-track having been cut through it about a year prior to 

 my visit. This had been very little used, so, with the excep- 

 tion of some trifling damage by wild pigs, that part of the 

 forest was fairly unmodified. Its trees are low, varying in 

 height from 6 m. to 9 m., and their foliage forms a flat upper 

 surface, as does that of the lowland forest before described, 

 except that here and there Dracophyllum arboreum raises its 

 needle-like leaves slightly above the general level. The tree- 

 trunks are rarely straight, but lean at various angles. The 

 soil consists of black peat with a layer of brownish humus 



