88 SOUTHERN FIELD CROPS 



ing flower-cluster, usually borne at the extreme top of the 

 plant. This panicle carries the male or pollen-bearing 

 flowers, which are usually in groups of two flowers in a 

 spikelet. Each flower, on maturing, pushes forth three 

 anthers, or pollen cases, from which, on maturing, the fine 

 particles of pollen are set free, to be borne by the wind to 

 the silks of other corn plants. It has been estimated that 

 a single tassel may bear more than 40,000,000 pollen- 

 grains. 



The tassel usually appears two to four days before the 

 first silks are visible on the same plant ; this is a device to 

 prevent the pollination of the silk by the pollen from the 

 same plant. 



Numerous experiments have shown that the removal 

 of the tassels on half of the plants in a field does not ma- 

 terially influence the yield. 



88. Silks. Each silk originates where a grain should 

 be borne on the cob, from which position it grows until its 

 outer part reaches the air, beyond the tip of the shuck. 

 This free part of the silk is supplied with very minute 

 hairs, the purpose of which is to entangle and hold the 

 grains of pollen. (See Fig. 36, A.) In case a silk fails to 

 receive pollen, it may continue to grow to unusual length. 

 In case no pollen lodges on any particular silk, no grain 

 is formed at the point on the cob where that silk is 

 attached. 



89. Pollination. Pollination is the transfer of pollen 

 to the sticky surface of the stigma, which in this case is 

 the silk. Along the entire length of the silk grows the 

 pollen-tube (Fig. 36), thrown out by the pollen-grain 

 after lodgment on the silk, 



