Studies on Cyanopliyceae. 219 
the manner of a Chroococcus or Gloeocapsa. This is the only indication 
I have had of the occurrence of such a stage in the life-cycle of 
Anabaena, such as has been suggested by Hansgirg and others. 
The fact remains, however, as Brand 1 has also pointed out, that 
Gloeocapsa and other unicellular Cyanophyceae are almost invariably 
associated with these filamentous forms; this was also the case in 
the material in question. 
In the first type of germination to be described the contents 
are slowly protruded from the spore, apparently by the excretion of 
mucilage from the protoplast. The emission of the contents is a 
very gradual one,—probably taking several hours, if not days and 
the stages figured are therefore derived from the germination of 
different spores. Large numbers of cases were observed, repre¬ 
senting all intermediate stages, and I think there can be no doubt of 
the phenomenon taking place as now described. The first indication 
of the commencing protrusion of the contents is their contraction 
and the appearance of a small colourless papilla at one end of the 
spore (Fig. 22); apparently this is in direct continuity with the 
protoplasmic contents, still enclosed in the membranes of the spore. 
This papilla (cf. p. 37 of the second article of the series) apparently 
pushes its way through the terminal portion of the exospore (which 
has perhaps in these cases not formed fully around this end of the 
spore ?), which surrounds it like a sheath ; the colourless papilla itself 
is probably the terminal portion of the inner investment, which is 
pushed out in advance of the escaping protoplast and probably serves 
to protect it at first. The papilla is gradually followed by the proto¬ 
plasmic contents, which leave a space behind them, occupied by 
colourless mucilage (cf. Figs. 21, 23, 24, 25 and 26). The aperture 
at the end of the spore, through which the contents pass out is 
often so narrow that they are distinctly compressed at this point, 
acquiring a biscuit-like shape (Figs. 20 and 25), and recalling the 
shape of the zoospore of a Vaucheria during its escape from the 
zoosporanginm. Numerous stages with the contents half liberated 
in this manner were observed (Figs. 23, 24 and 25), and formed 
an illustrative transition to cases in which only a small portion of 
the contents still remained inside the spore (Fig. 26). Their entire 
liberation is followed by the escape of the mucilage, to which it is 
due, and this is then generally visible surrounding the liberated 
spore-contents as a thin, transparent envelope of a spherical 
shape, 1 and of about three times the diameter of the spore (Fig. 15} 
1 Loc. cit., p. 46. 
