48 
Barber . — On the Structure and 
beginning to curve downwards. There is a great gap in the 
series between this specimen and the next. A gradual down- 
ward growth of the umbrella-shaped appendage must be 
assumed, accompanied by a formation of finger-like processes 
at its edge. There is at the same time a considerable increase 
in size of all the parts, and there appears also the twist in the 
stalk which is characteristic of the species. In the further 
description of the finger-shaped processes I shall make use of 
the term ‘ hapteres ’ introduced by Warming 1 for the peculiar 
organs of attachment among the Podostemaceae, and applied 
by Wille 2 and others to the fixing organs of Laminaria. The 
primary organ of fixation is not so easily included under the 
term, because it is part of the main stem and not an outgrowth 
from it. It differs furthermore from the hapteres in its ana- 
tomical structure, possessing as it does a central strand of 
elongated cells. 
In Fig. 4 the primary organ of fixation is seen from below 
inside the bell : there is only one circle of hapteres developed. 
Fig. 5 represents a stage at which three such circles are being 
formed. The oldest are already fixed ; the part of the bell 
above these has expanded considerably by intercalary growth, 
and the second row of hapteres now occupies the position 
formerly taken up by the first row. The third row is just 
appearing above the second. It will readily be seen from the 
figures that on attachment the distal ends of the hapteres 
become disc-shaped. 
In Fig. 6 this mode of growth has proceeded further. Here 
the excessive growth of the upper part of the bell has resulted 
in the formation of a flat hollow bulb. Four successive circles 
of hapteres have made their appearance, three of which are 
represented in the ground-plan (Fig. 7), while the fourth is not 
visible from the under-surface of the bulb. The degree of 
1 Bot. Zeit, Notizen, No. 12, 1883. ‘These hapteres arise exogenetically, and 
their branches are exogenous. They grow principally at the apex, and have a 
naked end (i. e. covered by no root-cap). They are formed of parenchyma alone, 
without trace of vascular bundle.’ 
2 Bot. Centralblatt, xxvii, 1-6. 
