The Morphology of Ruppia Maritima. 129 



kurzer. abgestumpfter. zuweilen etwas ausgehohlter freier Fortsatz/" 

 This develops still further during the growth of the young flower, 

 and sections of it are shown in PL IX, lig. 51. Irmisch suggests that this 

 structure corresponds to the pseudoperianth-segment of Potamogeton, 

 which Ascherson i'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 iiberragten 

 Anhangseln des Mittelbandes " (1889, p. 207). Eichler (1875, Pt. 1, 

 pp. 89— 91 1 had also supported Irmisch's view. 



Celakovsky iT896. pp. 48, 49'i, on the other hand, believes that 

 the^e scaly outgrowths from the connective represent reduced floral 

 leaves iPerigonblatter\ and deprecates the supposition that the}- 

 are morphologicalh- 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 

 onh- floral leaves which have become attached to the connective 

 at its base, mentioning Hegelmaier's (1870j work as one foundation 

 for his opinions. 



The development from the comiective in Potamogeton resembles 

 strongh" 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 awa}', the same sort of structures ma}- be 

 seen, two in number, at the base of the group of four pistils, and 

 opposite each other. These small structures show a ver}' minute 

 projection, the outgro^^■th of the connective, as was noted in the 

 young flower TPl. IX. flg. 50; and below, on opposite sides of it, 

 the scars showing the places where the thecae were formerl}' 

 attached. 



Without gomg into detail, m}- own opinion is that the connective 

 outgrowths in Potamogeton represent morphological!}- 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- 

 dimentar}- condition of the perianth segment. 



It win be seen that the appearance of the thecae m the young 

 stage represented by PI. IX, fig. 50 is much different from that in 

 PI. IX, fiff. 49. As the rhachis elono-ates. the thecae ctow in a 



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