306 



OKGANOGRAPHT. 



carpel opens by its dorsal suture or through the back of the 

 cells, the dissepiments remaining undivided {fig 657). Here, 

 each valve is composed of tlie united halves of two adjoining 

 carpels, and the valves are said to bear the dissepiments in the 

 middle. Examples maybe seen in the Lily, Iris {fig. 690), and 

 Hibiscus {fig. 657 ). As in septicidal dehiscence, the valves may 

 either carry the placentas and seeds with them {fig. 658), as in 

 the Iris; or they may break away from the placentas, and leave 

 them united in the form of a central column {fig. 659) ; or each 

 carpel may simply open at its dorsal suture, and tlie valves 

 bearing the dissepiments may remain attached to the placentas. 

 In some forms of septicidal dehiscence the carpels separate 

 ■without opening, as in the Digitalis, in which case tliey may 

 afterwards open by their dorsal sutures, or in a locullcidal 

 manner. In other cases, the axis is prolonged in the form of a 

 columella or carpophore, as in tlie Mallow, Castor-oil Plant 

 {fig. 660, a), and in the Geraniacea? {fig. 661, a), Umbelliferie 



Fig. 660. 



Fig. 661. 



Fig. 660. Fruit of Castor-Oil Plant (Riclrms 

 communis), dehiscing in a septicidal man- 

 ner, c, c, c. Carpels, a. Columella. i>d. 

 Dorsal suture where each i-arpel ulti- 

 mately opens Fin. «<>!. Fruit of a species of Geranium, c. Per- 

 sistent calyx, a. Axis or carpopliore from which the carpels, o, o, with 

 their styles, t, t, are separating, s. Stigmas. 



{fig. 697), &c., and the carjicls wliich arc united to it also 

 sei)arate without oi)eniiig. Such carpels frequently open after- 

 war.ls by their dorsal sutures (fig. 660, sd). When such carpels 

 separate with a certain amount of elasticity from the axis to 

 which they are attached, as in some Euphorbiaccjv, they have 

 been called cocci {fig. 660). By some botanists, all carpels which 

 thus separate from tlie axis in a septicidal manner are termed 

 cocci, and the fiiiit is described as dicoccous, tricoccous, Sec, 

 according t(j their numl)er. In some fruits, such as those of 

 the Linum caf/iurticiwi, the carpels open lirst by their dorsal 



