TERATOLOGY. DEGENERATION. 313 



apetalous trimerous staminal flower ; in fig. 546 one of the stamens is 

 suppressed and in fig. 547 two of them are awanting. Again in figs. 

 548, 549, 550, the calyx is suppressed, and its place occupied by one, 

 two, or three bracts (so that the flower is, properly speaking, achla- 

 mydeous), and only one or two stamens produced. In fig. 550, 1, 

 there is a sterile flower, consisting of a single stamen with a bract ; and 

 in fig. 550, 2, a fertile flower, consisting of a single carpel with a bract. 

 There is thus traced a degradation, as it is called, from a flower with 

 three stamens and three divisions of the calyx, to one with a single 

 bract and a single stamen or carpel. 



650. It is common to find some of the buds of a plant suppressed, 

 thus altering the spiral arrangement. Such, buds, however, are often 

 capable of being developed, if any accident occurs, or if the plant is 

 pruned. Deficiency of light and of air, and want of proper nourish- 

 ment, are capable of producing abortions of various kinds. The non- 

 development of a branch gives rise to clustered or fascicled (fastis, a 

 bundle of twigs) leaves, as in the Larch, and to fascicled twigs, as 

 in a common bird-nest-like monstrosity of the Birch. When the 

 true leaves of a plant are suppressed, their place may be occupied 

 by a tendril, as in Lathyrus Aphaca, in which the stipules perform the 

 functions of leaves (^[ 201) ; or the petiole may be developed in a 

 peculiar way, as in the phyllodia (^[ 157) of some Acacias. 



651. Degeneration, or the transformation of parts, often give rise 

 either to an apparent want of symmetry, or to irregularity in form. 

 Branches, when not properly developed, may assume the form of thorns 

 or spines (^[ 200), as in the Hawthorn and Wild-plum ; and by cul- 

 ture these spines may be converted into leaf-bearing branches. Leaves 

 often become mere scales, as in Lathrasa, Orobanche, and in Bulbs. 

 The limb of the calyx may appear as a rim, as in some Umbelliferse ; 

 or as pappus, in Composite and Valeriana. In Scrophularia, the 

 fifth stamen appears as a scale-like body, called staminodium (fig. 346); 

 in many other plants belonging to the Scrophulariacese, it assumes the 

 form of a filament, with hairs at its apex in place of an anther. In 

 unisexual flowers, it is not uncommon to find vestiges of the un- 

 developed stamens in the form of filiform bodies or scales. To many 

 of these staminal degenerations, Linnreus gave the name of nectaries. 

 In double flowers, transformations of the stamens and pistils take place, 

 so that they appear as petals. In Canna?, what are called petals are 

 in reality metamorphosed stamens. Allusion has already been made 

 to the various changes which the different parts of the flower thus 

 undergo. The object of the florist is to produce such monstrosities ; 

 and flowers, which by him are considered perfect, are looked upon by 

 the botanist as imperfect, from the want of the essential organs. 



652. Adhesion, or the growing together of parts, is a very common 

 cause of changes both as regards form and symmetry. The union of 



