=Increased number of leaves in a whorl.=--This may arise from actual multiplication, or from lateral chorisis, or fission. The true nature of the case may usually be ascertained by an examination of the distribution of the veins of the leaves, or of the fibrous cords of the stem, by the relative position of the supernumerary organs, &c. Among plants with normally opposite leaves the following occasionally produce them in whorls of three:--_Lonicera brachypoda_, _L. Xylosteum_, _Weigela rosea_, _Cornus mas_, _Vinca minor_, &c. _Paris quadrifolia_ may frequently be met with five leaves in its whorl, or even six.[398] =Increased number of bracts.=--This is not of infrequent occurrence; one of the most curious instances is that recorded by Mr. Edwards[399] in _Cerastium glomeratum_, where, in place of the usual pair of bracts at the base of the head of flowers, there was a whorl of six or eight, forming an involucre. The flowers in this case were apetalous and imperfect. =Polyphylly of the calyx.=--This may occur without any other perceptible change, while at other times the number of the other parts of the flower is proportionately increased. In a flower of a plum six sepals in place of five sometimes exist; a precisely similar occurrence in the flowers of the elder (_Sambucus_), the _Fuchsia_, and of _OEnanthe crocata_, may occasionally be met with. In the latter case, indeed, there are sometimes as many as ten segments to the calyx, and this without the other parts of the flower being correspondingly augmented. Among monocotyledons a similar increase is not uncommon, as in _Tulipa_, _Allium_, _Iris_, _Narcissus_, &c. In some plants there seems to exist normally much variation in the number of parts; thus in some species of _Lacistema_ in adjacent flowers the calyx may be found with four, five, or six segments. Most of these cases of polyphylly affecting the calyx may be explained by lateral chorisis or fission. =Polyphylly of the corolla.=--This may happen in connection with similar alterations in the calyx and stamens, or sometimes as an isolated occurrence. In the latter case it may be due to lateral chorisis, to substitution, or to the development of organs usually suppressed; thus, when in aconites we meet with four or five horn-like nectaries (petals) instead of two only, as usual, the supernumerary ones are accounted for by the inordinate development of parts which ordinarily are in an abortive or rudimentary state only. This is borne out by what happens in _Balsamineae_. In the common garden balsam the fifth petal is occasionally present, while in _Hydrocera triflora_ this petal is always present.