ORGANS OF REPRODUCTION. 



365 



five stamens, and five petals, but only three sepals; here two 

 sepals are suppressed: in Tropatolum pentaphyllum {fiy. 778), 



Fig. lib. 



Fig. 776. 



Fig. 777. 



Fig. 775. Diagram of the flower of the Heart's-ease Fig. 776. Diagram of a 



Leguminous flower Fig. 111. Diagram of tlie flower of Impatiem purvijiora. 



there are five sepals, and but two petals; three of the latter 

 being suppressed. In the Labiatae and Scrophulariaceae one of 

 the stamens is commonly suppressed, and sometimes three; 



Fig. 779. 



(? s> 



e^ 





Fig. 778. Diagram of tlie flower of Tropceohtm pcnta- 



phi/JJum. Fig. 77f>. Diagram of flowers of Euphor- 



biaceons Plants becoming more and more simple. 

 After Jiissieii. 



1. Staminate flower of Tragia cannabina. 



2. „ „ Tragia volubilis. 



3. r> " Anthostemn senrgnlensa. 



4. „ „ Andenopehis colliguaya. 



5. „ „ Euphorbia. 



thus in the Lamium {fig. 992) we have five parts to the calyx 

 and corolla, but only four stamens; and in the Salvia (fig. 995) 

 we have also five parts to the calyx and corolla, but only two 

 perfect stamens. 



The suppression of whorls and parts of a whorl are well 

 illustrated by plants of the Euphorbiaceae, and the above 

 diagram from Jussieu will show this fact in a remarkable 

 manner (fig. 779). Thus, in Xo. 1 we liave a flower consist- 

 ing of but two whorls, the petals and carpels being suppressed; 

 in No. 2, while the same whorls are present, one of the stamens 

 is absent; in No. 3 two stamens are suppressed; in Xo. 4 the 

 calyx is suppressed, and one stamen, the place of the calyx 

 being occupied by three bracts; Avhile in No. 5 the place of the 



