FEMALE ORGANS. 



53 



Some of the foregoing diagrams explain these laws : a is a leaf ; b, a leaf rolled 

 up preparatory to its conversion into a carpel ; c and k, a carpel ; d and I, 

 three carpels approximated, but not united ; e and m, the same united at the 

 ovaries, but disunited at the styles ; f and , these completely united into 

 one ovary, one style, and one stigma. 



435. All dissepiments whose position is at variance with 

 the foregoing laws are spurious. 



436. Spurious dissepiments derive their origin from various 

 causes, and may have either a vertical or horizontal position. 



437. When they are horizontal they are called phmgmata, 

 and are formed by the distension of the lining of the ovary ; 

 Ex. Cathartocarpus, Fistula. 



438. If vertical, they either are projections from the back 

 of the carpel, as in Amelanchier and Thespesia* ; or they are 

 caused by modifications of the placentae, as in Martynia, Didy- 

 mocarpus, and Cruciferae ; or they are produced by the turn- 

 ing inwards of the margins of the carpels*. 



The singular fruit of Diplophractum 244 , consisting of five cavities in the axis, sur- 

 rounded by five two-celled cavities at the circumference, must be composed of 

 carpels constructed as just described, and arranged in several series (420). 

 This is explained by the following cut, where 244 is a section of the fruit of 

 Diplophractum ; 242 shows an ideal arrangement of fifteen carpels in three 

 rows, five being external and perfect, with the margins of the carpels turned 

 inwards (406) ; five being altogether imperfect, and the five in the centre 

 being less imperfect. 243 shows the transverse section of this ideal figure. 

 In the ripe fruit we must suppose the intermediate carpels to be obliterated, 

 and the spurious dissepiments of the external carpels to be pressed up against 

 their back, so as to bisect the cavity of each carpel. 



