It is curious to observe in many of these cases that the transposed organ not only occupies the place of a suppressed or abortive organ, but frequently assumes its colour, and, to some extent, its function. This has been alluded to in the case of the leaf of _Gesnera_ (see p. 88) and in Orchids this replacement seems to be very common; thus, in addition to the cases before mentioned, in a flower of an Odontoglossum, for which I am indebted to Professor Oliver, the two lateral sepals were united together and occupied the position of the labellum, which was absent. A similar occurrence happens occasionally in _Lycaste Skinneri_, thus recalling the structure of _Masdevallia_, where the labellum is normally very small. The arrangement in Lycaste may thus be symbolised:
[Transcriber's note: The underscores represent a horizontal curly brace in the original.]
the + indicating the position of the absent labellum.
Cases of this kind are the more interesting from their relation to the fertilization of these flowers by insects; it seems as though, when the labellum, which performs so important an office in attracting and guiding insects, is deficient, its place is supplied by other means.
Displacement of the parts of the flower from elongation of the receptacle is a not infrequent teratological occurrence, resulting sometimes in the conversion of the verticillate into the spiral arrangement. Instances of this are cited under Elongation, Prolification, &c. In this place it is merely necessary to refer to a curious circumstance that is met with in some double flowers, owing to this separation of some parts of the flower and the cohesion or adhesion of others. Thus, in some double flowers of _Primula sinensis_ and in the Pea (_Pisum sativum_), I have seen a gradual passage of sepals to petals, so that the calyx and corolla formed one continuous sheet, winding spirally around the central axis of the flower, after the fashion of a spiral tube.[98]
=Displacement of the carpels= arises from one or other of the causes above alluded to, and when suppression takes place in this whorl it generally happens that the place of the suppressed organ is occupied by one of the remaining ones, which thus becomes partially dislocated.