398 
MARSILIACE^. 
Valentine’s figure.^ The shaded bodies represent the so-called 
pistils of Jussieu, and one of these detached is represented be- 
low, with its gelatinous covering, the result of immersion in 
water. The upper part of each cell is occupied 
by smaller granules, which are described as 
stamens, but this appears a somewhat vague 
conjecture, their office as such never having 
been clearly proved. Whatever may be the 
correct designation of the larger granules in 
their earlier state, it is quite certain that they 
ultimately become true seeds ; for both the 
authors quoted have succeeded in tracing their germination, 
and have recorded their observations on the subject with a close 
correspondence which mutually proves their accuracy and pre- 
cision ; the improvement in the structure of microscopes, and 
the more artistical drawing of Mr. Valentine, giving however a 
decided superiority to his illustrations. These observations are 
made on the assumption that Mr. Valentine was entirely unac- 
quainted with the contents of M. Jussieu’s admirable essay, 
which, from an observation in his introductory remarks, I most 
readily believe. 
According to Jussieu the seeds of Pilularia are to be found 
in the months of September and October, floating on the sur- 
face of the water, and germinating in that situation. 
This germination of the sporules is minutely described by 
Mr. Valentine. — “ The first external sign of germination is either 
the appearance of four cells projecting through the apex of the 
conical projection, or a gradual sw^elling of that part. * 
The enlarging cellular mass then distends the conical projection, 
unfolding the plicae of that body, and at length appears exter- 
nally with four of its cells projecting beyond the general mass, 
and compressed into a quadrangular form. ^ ^ Soon after 
the exposure of the entire germ, which is effected by the reflec- 
tion of the valves [of the internal membrane] and conical mem- 
brane over the side of the spomle, where they lie quite concealed 
by the germ, little fibrillae or rootlets begin to shoot from one 
^ Trans. Linn. Soc. xviii. tab. 35, fig. 30. 
