18 



As the valves dry their edges come together and the seeds are 

 squeezed out with some force and projected, just as a boy squeezing 

 an orange pip between his finger and thumb shoots it across the 

 room. In one case all the seeds have been squeezed out, and the 

 sides of the valve, or rather the contiguous halves of the neighbouring 

 carpels, are in contact. 



In the flax (PI. VII, fig. i8) the carpels open first along the 

 dorsal suture, and then separate from each other along the line of 

 juncture of the carpels, and we thus get twice as many divisions as 

 the number of carpels. 



When the walls of the carpels split away so as to leave a central 

 part to which the seeds are attached, we get the third form of 

 dehiscence. In the convolvulus (PI. VII, fig. 19) two of the fruits 

 have not yet opened. One has the outer walls splitting off, the 

 seeds remaining in the angles of the radiating walls, while in the 

 other the outer walls and seeds have fallen away. 



The fruit of Streptocarpus (PI. VII, fig. 20), a plant I came 

 across in a friend's greenhouse, struck me as being very peculiar at 

 first, as having a spiral dehiscence. However, on examination one 

 sees that the carpels form a spire, and the dehiscence is simply 

 longitudinal. One fruit is not yet ripe, but shows the line of 

 dehiscence, while the other is fully developed. 



Dehiscence, instead of being longitudinal as in the previous 

 examples, may be transverse. The fruit in this case is called a 

 pyxidium. In the henbane (PI. VII, fig. 21) we have a good 

 example of this. The lowest fruit is surrounded by the persistent 

 calyx. In the next two, half of the calyx has been cut away, showing 

 the complete fruit in the upper one, and in the lower one the lid 

 has fallen off. 



Another pretty example is seen in the pimpernel (PI. VII, fig. 22). 

 Two of the fruits are complete; in one the lid has nearly fallen off, 

 while in another it has gone, exposing the seeds, which are attached 

 to a free central placenta. 



Other capsules open by means of pores. In the poppy (PL VIII, 

 fig. 23) these are formed just beneath the flat stigmatic surface. 

 Thus we have a sort of pepper-pot arrangement that allows the loose 

 seeds inside to be occasionally scattered when the stem is shaken 

 violently by the wind, or jarred by some animal brushing against it. 



In the snap-dragon (PI. VIII, fig. 24) three pores may be seen 

 towards the apex of the capsule. 



The capsule is, strictly speaking, a superior fruit. In the iris 

 (PI. VIII, fig. 25) we have a fruit which only differs from this in 

 being inferior, and to distinguish it from a true capsule it is some- 

 times called a diplotegia. The dehiscence is down the middle of the 

 carpel, or along the dorsal suture. 



In the evening primrose (PI. VIII, fig. 26) we have another 

 inferior fruit, but in this case the valves separate from each other and 

 from the central axis. 



