The Morphology of Ruppia Maritima. 129 
kurzer, abgestumpfter, zuweilen etwas ausgehodhlter freier Fortsatz.” 
This develops still further during the growth of the young flower, 
and sections of it are shownin P1.1X, fig. 51. Irmisch suggests that this 
structure corresponds to the pseudoperianth-segment of Potamogeton, 
which Ascherson (1889) describes as a perianth-like dorsal appendage 
of the connective. <A similar development appears in Posidonia 
(Ascherson, 1889). That Ascherson agrees with Irmisch’s inter- 
pretation, is shown by his generic characterization of Ruppia: 
“Stb. 2, mit sehr kurzen, von den Antherenhalften tiberragten 
Anhangseln des Mittelbandes” (1889, p. 207). Eichler (1875, Pt. 4, 
pp. 89-91) had also supported Irmisch’s view. 
Celakovsky (1896, pp. 48, 49), on the other hand, believes that 
these scaly outgrowths from the connective represent reduced floral 
leaves (Perigonbliatter), and deprecates the supposition that they 
are morphologically portions of the anther connective. Eichler and 
Ascherson get their strongest argument, of course, from Potamogeton, 
which shows such a stronger development of this anther-connec- 
tive structure. Even here, however, Celakovsky (1896, 1. c.) sees 
only floral leaves which have become attached to the connective 
at its base, mentioning Hegelmaier’s (1870) work as one foundation 
for his opinions. 
The development from the connective in Potamogeton resembles 
strongly a floral leaf, although its connection with the anther-con- 
nective is quite pronounced. In the mature flower of Ruppia, after 
the stamens have fallen away, the same sort of structures may be 
seen, two in number, at the base of the group of four pistils, and 
opposite each other. These small structures show a very minute 
projection, the outgrowth of the connective, as was noted in the 
young flower (Pl. IX, fig. 50) and below, on opposite sides of it, 
the scars showing the places where the thecae were formerly 
attached. 
Without going into detail, my own opinion is that the connective 
outgrowths in Potamogeton represent morphologically perianth 
segments; that is, I agree with Celakovsky, and if this interpret- 
ation is true for Potamogeton, it must be true also for the evidently 
closely related Ruppia, which, as Celakovsky (1896, p. 49 and 1900, 
p. 49) emphasizes, is a reduced flower. The reduction is shown 
not merely in the smaller number of floral whorls, but in this ru- 
dimentary condition of the perianth segment. 
It will be seen that the appearance of the thecae in the young 
stage represented by Pl. IX, fig. 50 is much different from that in 
Pl. IX, fig. 49. As the rhachis elongates, the thecae grow in a 
