VEGETATION OF WHITE ISLAND. 43 
Upotiki on the mainland. Winds are frequent, principally from the west 
and south-west. The following figures, which will serve to indicate approx- 
imately the climate of White “Island for the year 1912-1913, are based on 
reports published iu the ‘ New Zealand Gazette.’ 
Tr КАНА: RAINFALL, AUCKLAND: TEMPERATURE. 
mm. Days. Mean max. °C. Mean min. °C. 
1912. July .......... 112 9 18:2 7.3 
Ацс........... 105 7 13:6 6:7 
Зерё........... 87 14 15:8 9-7 
Oct. .......... 104 8 16:6 10:1 
Nov....... 2... 3 8 17:7 11:2 
Dec........... 14 5 20-8 184 
1913. Jan. .......... 225 12 92:5 14:9 
Feb. .....,..., 19 4 22:8 14:9 
Mar. .......... 71 6 294 14-5 
Арг.......... . 17 1 18:4 10:6 
Мау.......... 58 7 14:4 8:2 
Tune.......... 35 4 140 06:0 
Means and totals ...... 940 85 17:6 10:7 
حح ست = — 
Sea-birds constitute a factor affecting the vegetation on White Island to 
some extent. The Gannet (Sula serrator) breeds in about six colonies on the 
south coast. Like the plants, its distribution is probably determined by the 
prevailing winds which carry fumes from the crater in а north-easterly 
direction. The areas occupied are quite clear of vegetation ; indeed the 
presence of dead plants of Metrosideros tomentosa in the midst of some of 
the colonies, shows that the birds not only prevent the scrub from spreading 
but actually kill any on ground they may occupy. In portions of the spaces 
cleared by Gannets, but not occupied at the time of my visit, there was a 
rank growth of herbaceous plants. 
Certain areas in the scrub and on slopes facing the sea are occupied by 
colonies of the Grey-faced Petrel (GZstrelata macroptera). These birds 
breed in burrows, and in the course of their breeding-season completely 
undermine and overturn the soil in the portions they occupy. Their effect 
on the vegetation is seen in the luxuriant growth of grasses and herbaceous 
plants on the slopes and edge of the scrub facing the sea. 
9 
Plant-formations. 
Scrub.—A belt of scrub runs along the south coast just above the sea- 
cliffs ; on the western end of the island there is a considerable area covered 
with scrub (see Plate 3); and оп the north coast are а few patches, increasing 
in size towards the west. Where occupied by Petrels the soil will be fairly 
