BN ALUS ACOROIDES. 
281 
after having given an account of the phenomena of pollina¬ 
tion of Vallisneria: “ Genau derselbe Vorgang findet bei 
Enalus statt.” Gf. also Goebel in “ Pflanzenbiol. Schilderun- 
gen ” II., 2, p. 365. To some extent there is an agreement, 
as the male flowers break off, rise to the surface and float 
isolated, driven by stream and wind, thus being carried to the 
pistillate flower. But as regards the manner in which the 
pollen is actually carried over to the stigmas of the female 
flower and—in connection therewith—also as regards the 
floral organization of both these plants there are consider¬ 
able differences. These depend upon the fact that Enalus is 
an oceanic plant exposed to the changes of high and low 
water. And it is with regard to this fact that the differences 
in the pollination between Vallisneria and Enalus obtain 
their full explanation. 
When the female flower of Enalus is in full anthesis the 
pedicel reaches such a height that the flowers during low 
water float on the surface, and during the lowest tide the 
uppermost part of the pedicel is also on the level of the 
surface of the water. By means of the above described 
wing-like spathe leaves the flower is kept floating in a hori¬ 
zontal position, viz., with the axis of the flower on a level 
with the surface of the water. The petals are now extended 
and float on the surface of the water without being wet, and 
as the spathe leaves are more or less strongly recurved they 
do not prevent the full exposition of the petals. The sepals 
still remain. The stigmas again are not so pushed out that 
they are exposed, but are covered as well by the basal parts 
of the petals as by the sepals (cf. PI. XXIV., A, fig. 8). 
When the male flowers arrive floating on the surface of the 
water they very easily get caught upon the petals, especially 
upon the folded edges, which are especially fitted to hold 
them fast, being just like the petals, very papillose. One 
may also observe little rows of captured male flowers along 
the edges of the petals, which hold them fast in spite of 
wind and currents. But no transport of pollen from these 
