THE, REPRODUCTIME ORGANS 
MorpeHoLoGy OF THE FLOWER 
As a preliminary to the account of the development of the flower 
and of the reproductive organs, it will perhaps be in the interests 
of clearness to preface a short description of the mature flower. 
In this connection I shall also take occasion to discuss briefly some 
of the more important morphological aspects of the flower. 
The flowers of Ruppia maritima are small, (83-5 mm. in diameter), 
consisting of two stamens and generally four pistils, with no perianth, 
and are borne in a pair at the apex of the peduncle, occurring 
one above the other, on opposite sides of the rhachis (PI. IX, fig. 49). 
The inflorescence is thus spadix-like, a type which is more pro- 
nounced in Potamogeton and Zostera. 
The mature stamen resembles two thick, rounded, semicircular 
bands closely appressed to the rhachis (PI1. IX, fig. 49), and meeting 
each other on opposite sides of it, each band being the half of an 
anther. In the Bonn Textbook (1908, p. 422), these anther-halves 
are called “ thecae,” and because this term is shorter and more specific, 
it will be used in this paper. A comparison with figure 474 of 
that textbook (1908, p. 422) demonstrates how a stamen of this 
sort could easily be evolved by a gradual separation of the thecae. 
In Ruppia their complete separation at maturity has led them to 
be interpreted as single stamens with bilocular anthers, for 
Roze (1894, p. 476) says: “Je n’ai pu y parvenir, car je n’ai 
jamais trouvé, dans les antheres meme jeunes, une adherence, 
une soudure quelconque qui le (1. e., cette dimimution du nombre 
des etamines) fit supposer. Et il est bien certain qu’a la maturité 
des organes, il est impossible de ne pas reconnaitre que chaque 
fleur presente quatre etamines parfaitement libres, ce qui est le point 
essentiel.” Pl. IX, fig. 50, however, gives a correct idea of the 
morphology of these thecae; for at this young stage the connective 
shows clearly that the structures on each side of it are merely the 
two thecae of the same stamen. 
At this point, it is interesting to note in PI. IX, fig. 50 the extension 
of the connective out beyond the plane of its attachment to the 
thecae, forming what is described by Irmisch (1851, p. 84) as “ein 
fT hag 
