90 - Transactions. 
Island, is distant about six hundred miles from New Zealand. Sunday . 
Island rises to a height of 1,720ft., and is the only one of the group 
which is forest-covered. The plant-covering of this island has been 
mild and equable, with many rainy days, considerable precipitation evenly 
distributed over the year, much wind in the winter months, and a con- 
stantly humid atmosphere. For the nine months February to October, 
1908, the total rainfall was 67-5in., on 176 days ; and the mean humidity 
was 91. e more elevated parts of the island are frequently enveloped 
in mist, and the plant-covering here is designated by Oliver “ wet forest." 
. There are, however, no permanent streams. Four species of Hymeno- 
phyllaceae occur in the wet forests, and the following description of them 
is taken from Oliver’s paper (p. 142): H. demissum is abundant every- 
where in wet forest, on branches of trees, tree-fern stems, and on the 
und. H. flabellatum is found in one place only, on the highest 
summit, the matted roots and close fronds covering the underside 
of a leaning trunk of Metrosideros villosa. T. humile is extremely rare, 
being found only on wet banks and fallen trunks of tree-ferns in deep 
shady ravines. T. venosum is an epiphyte of the wet forest found on the 
ning trunks and horizontal branches and on the tree- 
species. The four species of Hymenophyllaceae are all abundant in the 
North Island of New Zealand. The scanty distribution of this family 
in the Kermadecs is the more remarkable when the favourable nature of 
the forest is considered. From a study of the flora generally, Cheeseman 
concludes (9, p. 163) that the islands have been stocked with their plants 
y chance migrations across the ocean. 
The Chatham Islands lie about five hundred miles due east from New 
Zealand, in the latitude of Banks Peninsula, The largest of these is about 
thirty miles in length, its surface consisting, on the whole, of low elevations, 
relieved here and there by hills, of which those in the south attain a 
height of 600-940 ft. Forest covers a certain portion of the main island, 
both in the lowland and on the higher elevations, that of the latter being 
especially humid, with a close undergrowth of tree-ferns in many places 
and with an abundance of epiphytic ferns. Two papers dealing with the 
plant-covering have been published in the Transactions of the New Zea- 
land Institute, the first by Buchanan (6), who gave merely a list of plants 
collected from the main island, and the second by L. Cockayne (11), who 
dealt with the subject from an ecological point of view. The latter gives 
figures showing that at the eastern coast-line the average annual rainfall 
is 30-4 in., but that it is distributed over 186-6 days in the year, and adds 
that it must be reckoned exceedingly mild and equable, but that the winds 
are very frequent. Buchanan's list of Hymenophyllaceae occurring on the 
main island is as follows : H. bivalve, H. demissum, H. dilatatum, H. aus- 
trale, H. flabellatum, T. reniforme, and T. venosum; to which Cockayne 
