500 
The upright fronds ordinarily attain an age of two years, and sometimes they 
continue growing in the third year. This seems to be the case with the specimen 
represented in fig. 459 which was gathered in May. This frond has probably in 
the first year produced the first system of fans, in the second year the branches of 
these have produced a new system of fans, and in the year when the plant was 
gathered some of the branches have continued growing but have only caused a 
slight prolongation of the frond, 1 cm at most: the growing power of this frond 
was evidently exhausted. In the cases where the frond has arisen late in summer 
and therefore has only a 
small size at the end of 
the firstseason, the chance 
for a considerable growth 
in ihe third year may 
probably be greater. The 
period of growth begins 
in spring in the Danish 
waters and ceases towards 
the end of summer. The 
old fronds finally decay 
and are thrown off, pro- 
bably as a rule in autumn 
and winter; they are sepa- 
rated at the very base, 
leaving scars that are a 
\ | little deepened and have 
a slightly elevated border. 
Fig. 459. An attachment disc, ga- 
Chondrus crispus. Krageskovs Rev, 4 m, May. The short streaks above indicate th me HR Shoes 
the limit between the portions of the frond formed in the foregoing and the ered In Spring, SHOWE 
present year. Photo, 3/, nat. size. some 30 such scars and 
. a few upright shoots. Ac- 
cording to Prinrz the growth of the frond begins in Trondhjem Fjord about 
February and mostly ceases in August and September. 
The attachment disc has a parenchymatous structure of firm consistence 
(comp. DARBISHIRE p. 15, figs. 9—11), being built up of approximately quadrangular 
cells arranged in more or less vertical rows. The height of the cells is rather vari- 
able, from half to twice the breadth. The cell-walls are firm, not gelatinous, slaining 
deeply with hematoxylin. The outer wall is very thick, showing a lamellate struc- 
ture. The pits in the transverse walls are scarcely discernible except in the neigh- 
bourhood of the upright shoots. A stratification due to the periodical growth of the 
crust appears in older crusts, but it is rather irregular, probably depending on the 
production of the upright shoots. The cells are filled with starch grains. 
The upright fronds arise as outgrowths from the basal disc. A vertical section 
