374 PLEIOTAXY. 
Cornus mas and C. suecica sometimes show a triple 
involucre.! Irmish? records an analogous case in 
Anemone Hepatica, wherein the involucre was doubled. 
Similar augmentation occurs in cultivated Anemone. 
In addition to the plants already mentioned, Engelmann’® 
mentions as having produced bracts in unwonted 
numbers, Lythrwm Salicari ia, Plantago major, Veronica 
spicata, Hehiwm vulgare, Melilotus arvensis, and Rubus 
fruticosus. 
It must here be remarked that this great number of 
the bracts occurs naturally in such plants as Godoya, 
in which the bracts, or, as some consider them, the 
seoments of the calyx, are very numerous, and arranged 
in several overlapping segments. 
In some of the cultivated double varieties of Nigella 
the finely divided involucral bracts are repeated over 
and over again, but on a diminished scale, to the exclu- 
sion of all the other parts of the flower. 
Pleiotaxy or repetition of the calyx— The true calyx is 
very seldom affected in this manner, unless such organs 
as the epicalyx of mallows, Potentilla, &c., be considered 
as really parts of the calyx. 
In Linaria vulgaris Roeper observed a calyx con- 
sisting of a double series, each of five sepals, in con- 
junction with other changes. It is also common in 
double columbines, delphiniums, nigellas, &e. 
In the ‘Revue Horticole,’ 1867, p. 71, fig. 9, is de- 
scribed and figured by M. B. Verlot a curious variety 
of vine grown for years in the Botanic Garden at 
Grenoble, under the name of the double-flowered vine. 
The place of the flower is occupied by a large number 
of successive whorls of sepals disposed in regular 
order, and without any trace of the other portions of 
the flower. It is, in fact, more like a leaf-bud than a 
1 Weber, ‘ Verhandl. Nat. Hist. Vereins. Rhein. Pruss.,’ 1860. 
2 * Bot. Zeit.,’ 1848, p. 217. 
3 *De Anthol.,’ p. 17, § 12. 
4 «Tinnea,’ vol. ii, 1827, p. 85. ® 
