312 TERATOLOGY. SUPPRESSION OP ORGANS. 



carpels, flowers become unisexual (unus, one and sexu$, sex), or diclin- 

 ous (big, twice, and x^ivn, a bed), and are marked thus, $ $ ; the 

 first of these symbols indicating the male, and the second the female 

 flower. Thus, in Jatropha Curcas (fig. 314), the flowers have five 

 segments of the calyx, and five petals, while in some (fig. 314, 1) the 

 pistil is awanting; in others (fig. 314, 2), the stamens. In the genus 

 Lychnis, there are usually stamens and pistil present, or the flower is 

 hermaphrodite, or monoclinous (^o'j/oj, one, and x^tvn, a bed); but in 

 Lychnis dioica, some flowers have stamens only; others pistils only. 

 Thus it is that monoecious and dioecious (ftovo;, one, Si;, twice, and 

 OIKIOV, a habitation) plants are produced by the suppression of the essen- 

 tial organs of the flowers, either of the same or of different individuals 

 of the same species; while polygamous (oroAv?, many, and ya/tto?, mar- 

 riage) plants are those in which, besides unisexual, there are also her- 

 maphrodite or perfect flowers. 



649. Some parts of the pistil are generally suppressed hi the pro- 

 gress of growth, and hence it is rare to find it symmetrical with the 

 other whorls. When the fruit was treated of (^[ 522), it was shown 

 that carpels and ovules often become abortive by pressure and 

 absorption, so that the pericarp and seeds differ in their divisions 

 and number from the ovary and ovules. If the whorls of the calyx 

 and corolla are awanting, the flower becomes naked or achlamydeous 

 (If 351). It may still, however, be fitted for the functions of producing 

 seed; but if the essential organs, viz., the verticils of stamens and 

 pistils, are suppressed, then the flower, however showy as regards its 

 envelopes, is unfit for its functions, and is called neuter. Flowers hav- 

 ing stamens only, are staminiferous, staminal, sterile; or those having 

 pistils only, are pistilliferous, pistillate, or fertile. The suppression of 



54-3 546 547 548 549 550 



various verticils, and parts of them, is well seen in the family of the 

 Euphorbiacea3 (figs. 545 550). Thus, in fig. 545 is delineated an 



Figs. 545 550. Diagrams of flowers of Euphorbiaceous plants, becoming more and more 

 simple. (L) The calyx is the only envelope, and consists of three parts in figs. 545, 546, and 547. 

 It is completely suppressed in figs. 548, 549, and 550, and its place is occupied by a bract, in the 

 axil of which the flower is produced; this bract being accompanied in figs. 548 and 549 with two 

 small bractlets. (2.) The male flowers in fig. 545 have three stamens, in figs. 546 and 548 they 

 have two, in figs. 547 and 549 one stamen only is developed, and in fig. 550, 1, the solitary stamen 

 has only one anther-lobe. (3.) The female flower in fig. 550, 2, is reduced to a single carpel, with 

 a bract in the axil of which it is produced. 



Fig. 545. Diagram of a staminiferous flower of Tragia cannabina. 



Fig. 546. Diagram of a staminiferous flower of Tragia volubilis. 



Fig. 647. Diagram of a staminiferous flower of Anthostema senegalense. 



Fig. 548. Diagram of a staminiferous flower of Adenopeltis colliguaya. 



Fig. 549. Diagram of a staminiferous flower of a Euphorbia. 



Fig. 550. L Diagram of a staminiferous flower of Naias minor. 2. Of a pistilliferous flower of 

 Xaias major. 



