166 MR. T. 8. RALPH ON THE 
seems to recover strength and determination to ascend more 
straightly than before. 
It is to be observed that as the stem attains a height of ten feet, 
or thereabouts, the stipites become shorter, or, in other words, the 
pinne are set closer to the base of the stipites—but these last still 
continue close-pressed to the stem,—that the black colour above is 
replaced by а yellowish green, and greater asperities make their 
appearance beneath, and are extended now all the way up the 
rachis. The rachis in its outline is altered from the rounded to a 
flattened form ; and as it springs from the stem, it assures a gentle 
curve, so as to bring the frond to a horizontal position. The fronds 
аге now seldom more than twelve feet in length, and of such a 
weight as to require considerable effort to raise them off the ground 
by one end in order to shoulder them, when one may be readily 
carried. At this more mature stage of growth, the fronds, when 
fülly ripened, decay somewhere about six inches from their inser- 
tion into the stem, and no doubt suddenly fall from their hori- 
zontal position to a pendent one, and remain suspended perhaps 
during the greater part of the winter, giving a majestic tree fern 
the appearance of wearing a clothing of matting, much like a 
native chief. These fronds ultimately fall off, and leave the stem 
almost bare, so as to show the scars. This fern is seldom beset 
by climbing plants, —a circumstance possibly due to the long per- 
sistence of the stipital remains. 
If the stem of C. medullaris, of a height varying from 20 to 40 
feet, be examined, the following will be the features it will present. 
A large, rough, black, triangular-shaped buttress tapering upwards 
to 6 or 8 feet, when the original stem will most likely be seen 
marked with elliptical-shaped scars of 6 or 8 inches in length 
and about 3 іп width. As the eye is carried higher up, these scars 
will be seen to be set closer together, and to become altered in 
form ; and at a height of 20 feet and upwards, they become nearly 
hexagonal, and very regularly placed; so that six of them occupy 
the circumference, while the six above and those below alternate 
with them. The woody matter at this part is very hard and heavy 
with sap. 
I have counted about 84 or 86 fronds in full vigour in one 
crown at one time; and, supposing that a circle of fronds attain 
their full growth and live only six months, it will be seen that 
these ferns are slow growers. 
The linear form of the scars below accords with the brittle 
nature of the rachis and their mode of intortion, by which a great 
