Frtnts 



143 



dehiscence). When the wind blows through these sUts the thin 



flat seeds blow out at the top. If the fruit did not stand erect 



the seeds would be in danger of falling in a 



heap beneath the plant. When the split occurs 



between the carpels the dehiscence is septi- 



cidal. 



The "Poor Man's Weather-glass" {Ana- 

 gallis) and Hypoxis split around the centre 

 of the ovary so that the upper half falls off. 

 In Wahlenbergia a small triangular lid lifts 

 up at the top of each carpel. Mesembry- 

 anthemiim has a curious fruit. The capsule 

 is below the flower, and has from five to twenty 

 carpels. The seeds are borne near the base of 

 the carpels on long cords or funicles. The flowers open in 

 the sunshine. Do the fruits? Place some ripe fruits in a 

 glass of water. In a few minutes the roofs of the chambers 



Fig. 157. — Capsule 

 or pyxis of Ana- 

 gallis, with cir- 

 cumscissile de- 

 hiscence. (From 

 Thome and Ben- 

 nett's " Structu- 

 ral and Physiolo- 

 gical Botany.") 



Fig. 158.— The fruit of 71/e'.rt?w/^rj'a;A///ii!.v«w;« dehisce by triangular valves. (From 

 Henslow's " South African Flowering Plants.") 



will lift up and expose the seeds. Remove the fruits and 

 watch them close as they dry. Try the same experiment with 

 the fruits of Wahknhergia. Do the fruits act in the same 

 •way ? Meseinbryanthemtun thrives in the sun and the sand ; 



