374 Fritsch and Takeda . — On a Species of Chlamydomonas. 
as a space. The outer firmer part of the wall is very conspicuous, and 
reaches a thickness of about i /x. By using suitable stains such as acid 
fuchsin, safranin, erythrosine, or aniline blue, the inner gelatinous part 
is readily brought to view. In some cases it is more strongly developed at 
the posterior end of the cell (Figs. 4, 5, 8-10), a state found also in other 
species of Chlamydomonas and Carteria. Specimens have also occasionally 
been found in which the gelatinous layer is thickest at the anterior end 
(Fig. 7). In some cases this gelatinous part of the wall contains granules 
of an unknown substance 1 (cf. Fritsch, loc. cit., p. 344, and Fig. 1, F). 
The protoplast in living individuals is in direct contact with the inner 
gelatinous part of the cell-wall. In plasmolysed specimens a narrow clear 
zone is sometimes distinctly visible between the gelatinous layer and the 
protoplast. 
At the anterior end of the cell there are ordinarily two papillae 
(Figs. 1-7) which were wrongly interpreted as cilial apertures in the 
previous account (loc. cit., p. 341). These papillae are, however, solid pro- 
jections of the membrane, and the flagella do not pass through them, but 
emerge from the base on the abaxial side of each (cf. Figs. 7, 8, 10, 12). 
Whilst a considerable percentage of individuals exhibit two perfectly 
distinct papillae, all stages have been found connecting such forms with 
individuals in which there is but a single papilla (Fig. 11) ; the individuals 
shown in Figs. 8, 9, 10, and 12 illustrate intermediate conditions in which 
there is a single, more or less two-lobed, papilla. In shape the papillae are 
generally conical, with a rounded-truncate apex, although in some cases 
the conical character is less pronounced than in others. The papillae reach 
a height of 1-1*5 M* As far as we are aware this is the only known species 
of Chlamydomonas in which the papilla exhibits this character. We have 
not observed any further instances of the projection of the papillae on the 
inner side of the membrane as recorded in the earlier account (p. 342). 
The surface of the protoplast is always more or less irregular, appearing 
unevenly crenate in optical section (Figs. 1, 4, 5) and often showing short 
faint lines when viewed from the surface. These features lead to a false 
impression of striation of the protoplast, but the phenomenon is most 
probably due to granulation of the surface. Occasionally the lines show 
a certain regularity, analogous to that depicted in the figures in the previous 
account, but the individuals examined by us never exhibited true spiral 
striation, and it is likely that the earlier description was in error in this 
respect. 
At the anterior end the protoplast shows a well-marked colourless 
beak (loc. cit., p. 341), to the apex of which the two flagella are attached 
1 A similar feature has been observed in Carteria Fritschii , Tak., in which the inner gelatinous 
part of the cell-wall is often very well developed. For a description of this species see p. 369. 
