556 
been arrested by decay. A lateral branch often arises early near the dichotomy, and 
may then later suggest a trichotomy (fig. 545 A, C). Harvey's figure (1851, pl. 288) 
shows a specimen branched throughout by dichotomy, whereas KÜTzINGS picture 
1869, pl. 66 represents a specimen almost exclusively branched by lateral rami- 
fication. 
The thickness of the frond is nearly the same in its whole length, varying 
from 500 to 900 w. It increases a little from the growing apex downwards, but the 
increase does not continue gradually from the growing apex io the base of the 
frond. From a short distance downwards the diameter 
varies irregularly between 400—500 u and 900 x. The 
branches are often thinner at the base than at a higher 
level. The cross section of the frond is circular or a 
little oblong. 
The frond may often reach a height of 16 em but 
searcely exceeds this size. It is unknown how long 
it takes before this size is reached. The growth of the 
perennial frond ceases in winter and begins again 
in early spring. In a specimen collected in the middle 
of May, the new portions of the frond were 1 to 
1.5 cm, long, but I have not ascertained the annual 
increase in length of the frond. In a vigorous specimen 
from Frederikshayn (Deget) gathered in the middle of 
July I judged the increase of the year to be up to 
3 cm, and I think that the annual increase in length 
will not generally exceed this figure. If this is correct. 
| the tallest specimens should be at least 5 years 
4 i old. But the specimens may certainly become much 
nen older, for many shoots die entirely or in part and are 
Ahnjelia plicafa. A, frond branched £ 
by dichotomy. B, frond with dicho. replaced by new lateral shoots. In autumn specimens 
tomous and lateral ramification. C. may be met with in which a great number of the 
frond mainly with lateral ramifica- > > = i 
Hm OLES shoots have white tips, a sure sign of death and 
decay. The species often forms large carpets covering 
the upper or lateral faces of larger stones. Such carpets may certainly attain 
a great age, owing to the power of the expanded basal layer to produce 
new fronds. 
The colour of the frond depends on the amount of light to which it is exposed. 
When growing in shady places it is lurid, showing a characteristic violet tint when 
observed against the light, and the same is the case with the lower parts of older 
fronds in the shadow of the younger ones, but the upper part of ihe fronds which 
are exposed to the full day-light in summer are prettily green, in autumn yellowish 
green. In winter the young portions of the fronds are much darker, not very different 
in colour from the older ones. JONsson thinks that the darker colour of the older 
