THE EVOLUTION OF THE AEEOW 
31 
once. This is the explanation given by the bushmen of the 
Kalahari. There is only one real rainy season in the Kalahari 
and Bechuanaland ; but a few storms may occur at any time, 
and it is obvious that if the sama seed germinated at once after 
a few showers and the plants then died there would soon be 
none left to carry on the race. However, from my own ex- 
perience of the Kalahari I am convinced that the sama only 
grow once a year during the real rainy season from November 
to April, and the long period of germination noticed in my 
garden is probably to ensure the seeds only coming up during 
this season ; but on the other hand the seeds may not have been 
old enough. I still have some seeds left from the original 
consignment and it will be interesting to see whether they 
germinate more quickly next year, but in any case the explan- 
ation of this long period of germination does not seem at all 
clear. I believe it is the same in the case of Black Wattle seed, 
which I think is usually soaked in boiling water before it is 
planted. As an experiment I tried soaking sama seed in boil- 
ing water before planting, but none of the seeds ever came up. 
I do not know whether any other seeds are known which 
have a similar long period of germination, or whether the 
object of this is known. Perhaps some member will be able 
to give us further information on this subject. 
THE EVOLUTION OF THE AEEOW 
By C. W. Hobley 
This seems at first sight a trivial subject, but big issues 
sometimes hang on little things, and when one considers how 
through untold ages the fate of nations and the livelihood 
of mankind often hinged on this weapon its development 
may be considered worthy of some attention. It is beyond 
my powers to trace the history of the arrow through past ages, 
but my attention has been turned to the subject by some pre- 
historic arrow-heads which lately came into my possession 
and the various types of arrows used by the tribes in East 
