80 TILLERS OF THE GKOUND CHAP. 



all the palms produce fruit. Generally the Arabs 

 only grow the fruit-bearing trees in their gardens 

 and plantations, but in the flowering season they 

 gather the branches of the tree which bears no 

 fruit, as Herodotus explains, and tie them to the 

 fruit-bearing tree. These branches are full of the 

 dust which botanists call pollen, and riot till this 

 dust falls upon the flowers will they set to form 

 fruit. 



There are thus two kinds of date-palm trees, 

 the pollen-bearing and the fruit-bearing. In the 

 wild state the wind carries the dust from one 

 kind of tree to the other, but as the Arab does not 

 want to cultivate the pollen-bearing trees and get 

 nothing for his pains, he grows the fruit-bearing 

 only, and as they ripen gathers the dust spikes of 

 the other tree to fertilise his dates. We can explain 

 that very simply now, because about e, thousand 

 years after Mohammed a German botanist called 

 Camerarius first showed clearly that seeds never set 

 in flowers unless the fertilising dust falls upon the 

 pistil, which is a part of the seed-bearing organ. 



After Camerarius many other botanists worked 

 year after year, and they worked so well that now 

 every student of botany is shown things the 

 ancients never dreamt of, shown how the pollen 

 grains put out a little tube, which creeps down into 

 the seed-box and turns the little empty " ovules " 



