386 Fritsch, Observations on the young plants of Stigeoclonium Kütz, 
29. Szymansky (78): Über einige parasitische Algen. Breslau 1878. p. 12. 
30. West and West (02): A contribution to the Freshwater Algae of Ceylon. 
Trans. Linn. Soc. Vol. VI, part 3. 1902. 
31. Wille (90): Chaetophoraceae in Engler-Prantl, Die natürlichen Pflanzex- 
familien. I. Teil. 2. Abt. 1890, p. 86 etc. 
32. Wolle (87): Fresh-water Algae of the United States. Bethlehem 1857. 
Vol. U (Plates). 
Description of figures on Plates XI and XII. 
Plate XI (all figures magnified 375 times). 
Figs. 1—14, Stigeoclonium farcetum Berth. var. simplex nov, var. 
Figs. 1-5. Early stages in the formation ofthe base, which is already well- 
developed in Fig. 5. Each cell contains a single pyrenoid. 
Fig. 6. A two-celled hair, originating from one of the cells of the creeping, 
base, is seen at h. Its colourless, protoplasmic contents are indica- 
ted by shading: 
Fig. 7. A small base, some of the cells of which have liberated their con- 
tents as zoospores; a rhizoid is being given off below. 
Figs. 38, 9. The basal portion is relatively small and in each case bears a 
single, several-celled hair. The colourless, protoplasmie contents of 
the hair (p) are indicated by shading. 
Fig. 10. Base of the same kind, as that shown in figs. 8, 9, but bearing a 
normal upright filament with chlorophyll-containing cells. 
Figs. 11, 14. The basal portion is well-developed and bears a number ot 
upright branches on the side, which is slightly convex; these arise 
chiefly from its centre and from there radiate outwarts. The lowest 
cells of these branches are often narrower at the point of attach ment 
to the base than higher up in the filament. Apically (Fig. 14) the 
cells of these branches gradually pass over into narrower, colourless 
hair-cells. The cells of the upright filaments frequently contain two 
pyrenoids. 
Figs. 12, 13. An abnormal method of germination. An single upright fila- 
ment, whose basal cell is specially modified for attach ment, has 
been forıned. In Fig. 13 this basal cell is surrounded by a gra- 
nular mass of brownish-red matter. 
Figs. 15—21, Stigeoclonium variable Näg. 
Fig. 15. Single upright filament with modified basal cell. Both the lower 
e cells have lost their contents and are dead. 
Fig. 16. Upright branched filament, from the lowest cell of which a num- 
ber of branched rhizoids are given off. The cells of these latter 
are very poor in contents. 
Fig. 17. A 5-celled basal portion, consisting of dead and empty cells, and 
from which three branches are given oft. 
Fig. 18. A type of young plant, commonly found in this species; the simple, 
upright filaments have their apex curiously bent. T'he base of the 
filaments is surrounded by a dense mass of brownish-red matter (r., 
Fig. 19. Lower part of a filament, from which rhizoids are developing. The 
basal cell has developed three, one of these being unicellular. An- 
other rhizoid goes off from a cell higher up in the same filament. 
Fig. 20. Three-celled base, frequently tound in this species. The central cell 
has given rise to an upright filament, whilst the other two ar dead. 
Fig. 21. Simple upright filament, the lowest cell of which has developed a 
number of unicellular rhizoids. 
Figs. 22—25, Stigeoclonium nanum (Dillw.) Kütz. 
Figs. 22—24. Stages in the development of the first upright filament. The 
irregular line indicates the limit of the membrane of the 'Cladophora, 
on which tbe zoospore had cometo rest, In Figs. 22and 24, gisa 
