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A TEXTBOOK OF THEORETICAL BOTANY 



are contained, though so long as the flask retains an open mouth, the flower 

 is still called perigynous. But the extreme expression of this tendency to 

 enclosure of the carpels seems to be reached in those flowers in which the 

 carpels are not only enclosed, but organically fused to the inner wall of the 

 container, whose rim, bearing the outer organs of the flower, now seems to 

 have closed over the gynoecium and to be no longer distinguishable from 

 the ovary walls. The perianth and stamens are thus superposed on the 

 carpels and the flower is called epigynous (Fig. 1075). The relative position 

 of the gynoecium is also expressed by referring to it as superior and 

 inferior in the respective cases.* 



B 



Fig. 1075. — Longitudinal sections of epigynous flowers. A, Leiicojiini. 



B, Campanula. 



We have deliberately used the words " appears " and " seems " in the 

 above description, which reflects views long current, because the true course 

 of events in the development of epigyny has been much disputed. The one 

 point of general agreement is that epigyny is more advanced in an evolu- 

 tionary sense than hypogyny, and hence that the problem is the develop- 

 ment of the inferior ovary from the superior, rather than the reverse. 



There are three main theories, with variations. The oldest, which dates 

 from de CandoUe, looks upon the carpels as having been enclosed by the 

 concrescent bases of the other floral parts. This is called ^the^" appendi- 

 cular theory ", since these floral parts are regarded as phyllomes and hence 

 as appendages of the axis. The second theory considers the whole inferior 

 ovary as formed from the hollowed receptacle, the carpels being either non- 

 existent or else reduced to the styles and stigmas, with, sometimes, carpellary 

 placentae in the " ovary ". This is the " axial theory ". The third theory 

 also accepts the idea of the hollowed receptacle but maintains that the carpels 

 are present, fused to the inside of the receptacle cup. 



All three views are based upon an assumed antithesis between the axis 

 and its appendages which now seems old-fashioned, and it may be said that 



* For a fuller discussion of the problem of epigyny see p. 1 135 in the section on the floral 

 receptacle, and also p. 1137 in connection with the inferior ovary. 



