606 Transactions. 
of its lamina, are to be regarded as special modifications. Another stoutly- 
rowing species with considerable frond-modification is H. dilatatum. Here 
the extent of lamina is certainly, taking into consideration the size of 
the frond, the greatest in any of the New Zealand species. H. scabrum, 
H. sanguinolentum, and H. multifidum also show a large frond-development 
in the pendulous state, the first-named attaining an extreme length of 21 ft. 
to 3ft. In the mid-epiphytic station in the lowland forests the lateral 
pinnae of the fronds of H. sanguinolentum and of H. multifidum, as well 
as the main rhachis, frequently tend to elongate into tails. H. villosum, 
although a characteristic epiphyte, shows a poor extent of frond-lamina, 
and the frond preserves more or less invariably the erect deltoid form. To 
this statement must be added the fact that it is a mountain and not a low- 
land plant, and that whereas the mid-epiphytic station in the lowland 
forests enables the species to make the most use of atmospheric water by 
frond absorption, the same station in the mountain-forests, especially at 
such elevations as H. villosum can ascend to, where the atmospheric humidity 
is more variable, is of value rather on account of the water-supply in the 
damp mossy clothing of the tree-branches. When, however, it occurs as 
a low epiphyte at the bases of the ranges, in which localities and station 
there is a more constantly high atmospheric humidity, its fronds frequently 
show a well-marked tendency to an elongation of the main rhachis, and 
they may also be pendulous. 
The question arises regarding the open-creeping, strong-stemmed epi- 
phytes such as H. dilatatum, H. scabrum, a . reniforme, which in creek- 
beds at the base of the ranges can occur rupestrally and adopt a more erect 
habit of growth, as they do also very generally in the more light forests of 
other parts of New Zealand—why do they not also occur on the floor or on 
fallen logs in the lowland forests of Westland! It may be that with such 
species the need for light in the heavy dense forests causes them to keep 
to the epiphytic station, and it is to be noted that where in Westland they 
do occur terrestrially at higher altitudes it is in such less-shaded localities 
the larger surfaces of tree-trunks, but the other species of this class, with 
the exception of H. australe and H. villosum, prefer the under-side of 
