For figures or descriptions of four-leaved shamrocks the reader is referred to Lobel, 'Stirp. Advers.,' Nov., p. 382. Tabernaemontanus 'Krauterbuch,' S. 222. Schlechtendal, 'Bot. Zeit.,' ix, p. 583, xiv, p. 71. Maugin, 'Bull. Soc Bot. Fr.,' 1866, t. xiii, p. 279. See also Cramer, 'Bildungsabweich,' p. 92. Walpers, 'Linnaea,' 1840, p. 362 (7-leaved). Schlechtendal, 'Bot. Zeit.,' 1844, p. 457, _Cytisus_. Wigand, 'Flora,' 1856, p. 706. Frondiferous leaves have much the appearance of branches provided with leaves, and they may be compared with those instances in which an adventitious bud is placed on the surface or edges of the leaves, as in _Gesnera_, _Cardamine_, &c. In truth, the two conditions merge one into the other, as in some begonias, where the ramenta often become leaf-like and bear small bulbils in the axil. When frondiferous leaves die the appendages die also, but when a true bud has been formed on a leaf it does not of necessity die with the leaf that bears it, but separates from it and continues to grow independently. =Increased number of stipules, spathes, &c.=--Seringe relates the occasional presence of two or three additional stipules upon the leaf-stalks of _Salix fragilis_, and even makes a variety (_Salix pendula_, var. _multistipulata_). An increase in the number of the spathes has been often noticed in Arads[396]. Prof. Alex. Braun has studied this subject in some detail[397]. In _Calla palustris_ the shoot which continues the growth of the plant proceeds from the axil of the last leaf but one; the very last leaf producing no bud, but if accidentally a shoot is developed in this latter situation it produces flowers at once. No leaves are formed, but, on the contrary, two or three spathes surround the spadix, so that the presence of an increased number of spathes in this plant is associated with the development of a side shoot from the axil of the last leaf, the situation whence, under natural circumstances, no shoot at all issues. The supernumerary spathes are not always on the same level, but may be separated by a considerable interval. They vary very much in size, and sometimes assume the form and appearance of leaves. Similar anomalies occur in other Arads as _Arum maculatum_, _Richardia aethiopica_, and _Anthurium Scherzerianum_, frequently combined with a leaf-like appearance of the spathes and sometimes with a subdivision of the spadix into two or three branches. Engelmann relates the occurrence of an increased number of glumes in _Bromus velutinus_ associated with suppression of the flowers. =Polyphylly.=--As previously explained, this term is here applied to those cases in which the members of any particular whorl are increased in number, the whorls themselves not necessarily being augmented. The simplest cases of this kind are those in which we meet with an unusual number of leaves in a whorl.