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A TEXTBOOK OF THEORETICAL BOTANY 



Fig. 1 1 88. — Ontogeny of inferior ovaries. Carpels adnate to inner surface of floral cup. 

 A, B and C, Gladiolus communis. D, E and F, Gaura biennis. {After Payer.) 



original apex and the carpels (or at least the ovules, if we believe that no 

 carpels are formed) in inferior ovaries, and bearing upward with it some or 

 all of the outer whorls of floral parts. There is much in this that is gratuitous. 

 It has no analogy among vegetative axes, nor does it accord with what is 

 known of the processes of growth regulation. The idea of emergences 

 generally, and not in this particular case only, runs contrary to the experi- 

 ence of comparative morphology, which supports the belief that no organ 

 is wholly new but is produced by the modification of pre-existing structures 

 through a relatively limited number of processes, which recur in innumer- 

 able examples. Such are: subdivision, cohesion, concrescence, adnation, 

 changes of symmetry, reduction, suppression, etc. 



If we subscribe to this doctrine, which is very broadly based in nature, 

 we may call it the principle of precedence. It would at least lead us to 

 doubt the production of a new cupped formation of axial tissue emerging 

 from an otherwise terete axis, and not associated with the tangential cohe- 

 sion of existing appendages. 



To deny the possibility of such a structure on the basis of a general 

 theory such as that we have just suggested would be, however, to beg the 



