: On THE PITHOPHORACE. 1:7 
In by far the greatest part of sporiferous individuals, the spores 
are brought forth in all parts of the cauloid, and in almost all the cauloid 
cells. For these individuals I have employed the name fertile (pl. 2, 
fig. 1, 2, 3, 13). But in some sporiferous individuals we find, that 
spores are developed only in one part of the cauloid, while the other 
parts consist of cells which never develop spores. These individuals 
may be called half-fertile-half-sterile (pl. 2, fig. 6, 7). And the 
individuals in which no spores at all are ever developed, are the sterile. 
In the account of the construction of the vegetative system I have indi- 
cated (page 7), that another difference does also exist between the fer- 
tile and the sterile specimens, than the one consisting in the presence 
or absence of spores. We recollect that this difference, in short, consists 
in the circumstance, that the system of ramification is stronger developed 
in sterile than in fertile specimens. If we observe the half-fertile-half- 
sterile specimens somewhat nearer, we shall find that they are perfect 
connecting forms between the sterile and the fertile. The sporiferous 
part of the cauloid of the half-fertile-half-sterile specimens has a more 
feebly developed system of ramification, resembling that which is found 
in purely fertile specimens; the part which is not sporiferous has, on 
the contrary, a more strongly developed, resembling that of purely 
sterile specimens. Fig. 6 and 7 on pl. 2 represent two half-fertile-half- 
sterile specimens of P. kewensis nob. In the specimen represented fig. 
6 the upper part is fertile and the lower sterile; in the specimen repre- 
sented fig. 7 the lower part is fertile and the upper sterile. In both 
specimens, a very considerable difference exists between the system 
of ramification of the fertile and of the sterile parts. While the fertile 
part has short and few branches (several of the cells in the principal 
filament are branchless), the sterile part has comparatively long 
and numerous branches (all the cells of the principal filament carry 
at least one’ branch, and in the specimen represented fig. 7 we find 
several which carry two).—In the same manner as in P. kewensis nob. I 
have found half-fertile-half-sterile specimens in other species of Pithophorea. 
Although the sterile specimens do not develop spores, still they 
are not quite denied the possibility of reproduction. They have the 
power to develop another kind of reproductive cells, the so-called pro- 
lific’ cells. These cells are originated by common vegetative cells in 
the following manyer: some vegetative cells, very rich in chlorophyll, 
absorb food in a more abundant quantity than the others, and store up 
this food in themselves in the shape of granules of starch (pl. 3, fig. 1 p). 
Nova Acta Reg. Soc. Ups. Ser. III. 3 
