392 Proceedings of Philosophical Societies. [May, 
every country; but the flowers and fruit of this small and singular 
plant have not been examined with sufficient care. 
M_ le Baron de Beauvois is the first botanist who has been fortu- 
pate evough to collect ripe grains, and to make them germinate. 
He has followed the lemna thus obtained during its whole progress, 
and has completed its history, which Ehrhardt and Wolf had only 
sketched. f 
It results from the.observations of M. de Beauvois that the fower 
of duckmeat is hermaphrodite, with an envelope which is entire, 
with two stamina which unfold themselves in succession, with a 
single style, with a superior ovarium, which becomes an unilocular 
capsule, splitting circularly at the base, and containing from one to 
four seeds, which germinate like monocotyledinous seeds, but with 
very peculiar circumstances, the most remarkable of which is, that’ 
the parts considered as the radicle and plumula separate from the 
first leaf which they produce, and leave it alone to push out roots 
and other Jeaves. 
Another species of organised being, which covers, and often fills 
stagnant waters, is the conferva, consisting of a mass of green fila- 
ments, sometimes similar to a sort of felt, which some naturalists 
have wished to assign to the animal kingdom. Their propagation is 
a good deal different ; and some of them, whose filaments are at 
first disagreeably uniform, swell at intervals, and produce knots. 
from which new filaments proceed. This has induced M. Vaucher 
to give to these species the name of prolifere. But this botanist 
warns us not to confound with these filaments springing from the- 
plant itself certain parasitical confervee which attach themselves to 
other conferve, and which have the same appearance. 
M. Leclere de Laval, Member of the Chamber of Deputies, and 
a very assiduous observer, has presented to the Class a memoir, from 
which it appears that no other tilaments except these parasitical ones 
exist, and that the propagation of the confervae, improperly called: 
prolifer, takes place in the same way as in those called conjuge, 
by the concentration of the green matter contained in each interval 
between two cells into an isolated globule which issues from the 
plant at a certain time, and fixes itself on the first body it meets 
with in its fall; and, after having thrown out some filaments in 
order to fix itself, developes a loug series of cells. 
The author would give to this kind the name of auéarcite, instead 
of prolifer, which from his observations is improper. But as M. 
Desvaux, from other considerations, had given them the name of 
cyrtimus, in a memoir presented more than a year ago, it has been’ 
thought unnecessary to introduce a new change in the nomenclature. 
M. Henri de Cassini had presented to the Class in 1812 a memoir 
on the style and stigmata of synantherez of plants, usually said to 
possess a compound flower, and another on their stamina. ‘Towards 
the end of 1814 he presented a third paper, of which we could not 
give an account in our last analysis, because the report concerning” 
