POLYPHVLLV. 359 



other perceptible change, while at other times the 

 number of the other parts of the flower is proportion- 

 ately 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 (Samhicus)^ the 

 Fuchsia, and of (Enanthe crocata, may occasionally be 

 met with. In the latter case, indeed, there are some- 

 times 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 TiUipa, 

 Allium J Iris, Narcissus, &c. 



In some plants there seems to exist normally much 

 variation in the number of parts ; thus in some species 

 of La^isteina 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 connec- 

 tion 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 Balsamineoi. In the common garden balsam 

 the fifth petal is occasionally present, while in Uydrocera 

 triflora this petal is always present. 



In a flower of a Cyclamen recently examined there 

 were ten petals in one series, the additional five being 

 evidently due to the subdivision of the five primary 

 ones ; the natural circular plan of the flower was here 

 replaced by an elliptical one. A similar occurrence 

 takes place in the flowers of maples (Acer), which 

 sometimes show an increased number of parts in thoir 



