447 
(see above p. 440). In normal axillary shoots the first tricho- 
blast appears on the 3rd or 4th, more rarely on the 5th joint, 
the basal joint included. 
At the base of the plants 
endogenous creeping fila- 
ments are to be found 
which bear no trichoblasts; 
they may bend upwards 
and become erect, tricho- 
blast-bearing shoots (fig. 
Fig. 404. 410). Endogenous shoots 
Brongniartella byssoides. Communication arise from the creeping 
of the second joint of the trichoblast with 
the central cell of the basal joint. 220 : 1. 
and the lowermost part 
of the erect shoots, emerg- 
ing at the limit between two joints. Their first joint has 
pericentral cells on all sides. In these shoots a great number 
of joints is often without trichoblasts; but when the tricho- 
blasts appear they occur on all the joints (figs. 402, 410). 
FALKENBERG under the designation stolons describes 
certain shoots which bear no trichoblasts but are provided 
with rhizoids and have a long conical point. Such shoots 
are frequently met 
LY with in the Danish 
waters but they 
have not the char- 
acter of stolons. 
They occur often 
indeed, mostly in 
the lower part ofthe 
plants, but they are 
not creeping, the 
numerous rhizoids 
are directed forward 
and not fixed to 
any substratum and 
Fig. 405. therefore without 
Brongniartella byssoides. Lower part of trichoblasts ttach t di 
with axillary shoots. The pericentral cells of the attachmen ISG; 
basal joint parallel with the longitudinal axis of and such shoots 
the trichoblast, the axillary shoot nearly perpendic- Al à 5 
ular to this direction. 350 : 1. may also occur In 
the upper part of 
Fig. 406. 
Brongniartella byssoides. Spiny 
shoot without trichoblasts but 
with rhizoids or hairs. 30:1. 
the plants. Their appearance is in correlation with a weakening of the growing 
power. In certain long shoots the trichoblasts become gradually feebler, finally their 
7% 
5 
