164 МВ. T. S. RALPH ON THE 
C. Smithii, whose delicate spreading fronds of brighter green 
are mounted on a stem which is furnished with a wiry fibrous 
structure, and whose top is adorned (P) with the remains of the 
stipites of dead fronds, hanging closely to the stem, from sixty to 
seventy in number, but all divested of the pinnæ. This is what 
may be seen in the bush when uninjured by the action of violent 
winds. Thus much for a glance at these species; a more detailed 
account I now give, from investigations carried on uninterruptedly 
during three months. 
C. dealbata (White or Silver Fern) presents two or perhaps 
three forms; but the characters are scarcely marked enough to 
make out so many varieties. One state of the fern is marked by 
the frond being furnished with sori well within the margin, thus 
giving the appearance of a broader pinna, &c.; another form 
appears to be characterized by a more delicate frond; while а 
third is a coarse or hard-fronded form, with a yellowish hue along 
the upper side of the main and partial rachis, and which is per- 
ceptible at a distance—the pinnules are also inclined to curl 
inwards at the margins : this may be termed the full-fruited form, 
as the вог1 are very abundant. 
No decided character can be drawn from the persistence of the 
bases of the dead fronds. I have seen these stipital remains cover- 
ing a stem (of C. dealbata) from top to bottom, in others halfway 
up, in some on one side only ; seldom, however, is the stem entirely 
bare, but a wiry fibrous structure (aerial rootlets) issues out and 
covers it more completely. When this tree-fern has attained some 
size, the base gradually enlarges by the addition of these fibres, till 
it reaches perhaps a foot and a half in diameter. The greatest 
height to which it seems to attain is about 24 feet. The fronds 
vary from 8 feet to 12 feet in length and from 2 feet to 3 feet in 
breadth, and they spring out nearly horizontally from the crown. 
Although the fronds are so beautifully white underneath, it is 
almost impossible at times, even in open places, to be sure one 
sees a white-fronded fern; but a blow from a stick or a wave of 
the wind is necessary, to turn but a little portion of the frond, in 
order to satisfy the observer that it is white beneath. 
C. medullaris (Mamaku, or Mamagu of the natives, Black 
Fern of the settlers).—This fern may be recognized at a very early 
stage of its growth, and before any trunk has been developed, by 
the general form and texture of the young frond. The main rachis 
is usually of a very dark-brown or black colour. When it has 
formed a stem, it will be observed that these black stipites are 
