Ixxxvi The Transactions of the South African Philosophical Society 
by the impetus given them from some suddenly released and energeti- 
cally contracting fibres. Somewhat similar is the opening of the 
capsules of the sorrels, Ozalis, of which so many species embellish the 
green slopes of the Peninsula. The fruit of Pelargonium, a genus so 
largely represented in our flora, consists of five achenes, each crowned 
by the persistent and much elongated style. Achenes and styles cohere 
at their inner side, but when ripe they suddenly separate and jump 
away. Well known is the peculiarity of these achenes to bury them- 
selves in the ground with the assistance of the hygroscopic styles, which 
twist into corkscrew shape during dry weather and become straight 
again in damp air or in water. 
The nearly allied genus Geranium obtains the same result by a some- 
what different method. The fruitlets are one-seeded capsules which 
open at the outer side, and the styles do not separate completely, but 
remain joined at the tip. When the contraction takes place the cap- 
sules and lower parts of the styles separate suddenly and curve upwards, 
throwing out the seed as from a sling. 
In Goethe’s Italian journey there is a description of a little adventure. 
One night he was awakened by a number of little explosions in his 
room, and by some small projectiles touching his face. Wondering 
what the cause of it might be, he lit his candle and found that it was 
only a branch of Acanthus mollis gathered during the day, which kept 
up this bombardment. Our South African flora offers plenty of 
material for similar observation, for many Acanthace, ¢.g., Blepharis, 
Justicia, Duvernoia, possess explosive capsules, which, when ripe and 
dry, act like small catapults. If you take a branch of the Buchu plant, 
Barosma crenulata, or some species of Diosma with ripe capsules, and 
place it where the sun can reach it, you will soon be able to witness a 
similar performance, only in this case the endocarp would remain with 
the seeds. The pods of many Leguminose, e.g., Indigofera, Tephrosia, 
Podalyria, open suddenly, and the spirally twisting valves throw the 
seeds in all directions. 
This force is in some cases so considerable that the large seeds which 
I am exhibiting here, each weighing two grammes, are thrown to a 
distance of tenfeet. Unfortunately I cannot give you the name of this 
plant, the seeds having been brought from the Kalahari by a missionary, 
who gave me their Herero name Omaheke, and the information that the 
natives eat them. Well known is the scattering of the seeds of the 
castor-oil plant, Ricinus communis, which shares this power with most 
other Euphorbiacex, ¢g., EH. grandidens, E. candelabra, Hyenanche 
globosa, their seeds often reaching the ground fifteen, or even twenty, 
feet from the outermost branches. 
There is another point closely connected with our subject, which may 
