314 



TERATOLOGY. ADHESION. 



stems gives rise occasionally to anomalies, as in the fasdated stalk of 

 Cockscomb (fig. 230), and the flattened stems of some Conifers (^[ 197), 

 and probably also the peculiar stems of certain Sapindaceaa and Meni- 

 spermacea? of Brazil (^[ 90). Some of these, however, may perhaps 

 be traced not to adhesion, but to an abnornal development of buds, 

 producing wood only in one direction in place of all round. Natural 

 grafts occasionally occur from one branch of a tree uniting to another. 

 Boots also sometimes become grafted, and to this has been attributed 

 the vitality occasionally preserved by the stumps of Spruce-firs which 

 have been felled on the Swiss Alps. The union of two leaves by their 

 base, forms a connate leaf, and the adhesion of the lobes of a single 

 leaf on the opposite side of the stalk, gives rise to perfoliate leaves 

 (fig. 156). The union of the edges of a folded leaf forms Ascidia, or 

 pitchers (figs. 184, 187). The different parts of the same verticil of 

 the flower unite often more or less completely, giving rise to a mono- 

 phyllous or gamophyllous involucre (^[ 347); a monosepalous or 

 gamosepalous calyx (fig. 273); a monopetalous or gamopetalous corolla 

 (figs. 293, 294, &c.) ; monadelphous (figs. 307, 314, 1), diadelphous 

 (^[ 399), and polyadelphous (figs. 315, 551), stamens; syngenesious 

 anthers (^[417); a gynandrous column (^[ 400); and a syncarpous 

 ovary (fig. 383). The different verticils of the flower are frequently 



adherent. The calyx is often united to the corolla or to the stamens, 

 or both (fig. 308) ; the stamens may adhere to the corolla (fig. 552) ; 

 or there may be a union of the four verticils of the flower, so that the 

 calyx becomes superior (fig. 309). In some instances, when the axis 

 is elongated, adhesions take place between it and certain whorls of the 

 flower. Thus, in some Caryophyllaceae (fig. 553), the calyx, c, bear- 

 Fig. 551. One of the five bundles of stamens taken from the polyadelphous flower of Malva 

 miniata. Stamens are united by their filaments. 



Fig. 55-2. Portion of the gamopetalous or monopetalous corolla, p, of a Collomia, showing part 

 of the tube t. terminated by two lobes of the limb, I, and having the stamen, e, inserted into it, 

 and united to it, so that the upper part of the filament, i, only is free. 



