6 Veit Brecuer WirrrRock. 
manner adapted to the absorption of food, nor serves as an affixing 
organ of the plant. The Pithophoracee, at least those that grow in 
water, are, as a rule, not attached to other objects, but float free in 
the water. The terrestrial species, Pithophora Cleveana nob., on the 
contrary, very often have affixing organs, which serve at the same 
time the physiological purpose of assimilating organs,*) but these 
belong to the cauloid and not to the rhizoid part of the thallus. 
The general, outer shape of the thallus having now been described, 
a somewhat more extensive account of the nature of its two principal 
parts, the cauloid and the rhizoid, follows next. As I have mentioned 
above, the cauloid is, as a rule, ramified. Full-grown individuals with a 
wholly unbranched cauloid are very rare. Only im two species, P. Cleveana 
nob. and P. wqualis nob., I have found such specimens twice or trice (pl. 1, fig. 
5). In P. kewensis nob., individuals with very few and small branches (pl. 2, 
fig. 5) are sometimes found, but I have not seen wholly unbranched specimens 
of this species. The system of ramification is of different strength in different 
species. Itis feeblest in P. sumatrana (v. Mart.) nob., judging from the 
rather few and not quite perfect specimens that 1 have had opportunity 
to examine. Al] the branches, that exist here, proceed immediately out 
of the principal filament, and thus all the branches are of the 1:st degree. 
They are usually simple, but not rarely also opposite in pairs. P. kew- 
ensis nob. and P. Cleveana nob. generally have branches of only one 
degree (pl. 2, fig. 1, 6, 7, 13), but sometimes those branches ramify, and 
the branches they develop are then of the 2:d degree (pl. 2, fig. 3). In 
P. kewensis nob. the branches are always single; in P. Cleveana nob. 
they are not seldom opposite to each other (pl. 2, fig. 3). P. e@qualis 
nob. has two types of ramification. In one the branches are only of 
the 1:st degree, in the other also of the second. They are always single. 
In P. polymorpha nob. specimens are found with branches of but one degree, 
but also with two. The branches of the 1:st degree are not seldom placed 
opposite to each other (pl. 2, fig. 13). P. Zelleri (v. Mart.) nob. always 
has branches of two degrees, which are partly opposite. In P. Roettlera 
(Roth) nob. the ‘system of ramification is most powerfully developed. — 
Here branches of three orders are regularly found, of which those that 
belong to the l:st are placed three in a whorl, but those of the 2:d and 
3:rd_ placed singly or in pairs (pl. 2, fig. 18). From this we find, that 
1) Regarding these, which are also now and then found in the aquatic species, 
see pages 10 and 25, 
To: 
