BREAD PLANTS 49 



How much play has the blade independent of the 

 swinging sheath? What amount of play has the 

 whole leaf? 



The leaf has a spiral twist in i^s midrib that 

 enables it to avoid the full force of the wind. The 

 frills enable the midrib to turn to left or right, 

 almost as easily as if it were hinged. By swinging 

 round the stalk, and getting out of the way as 

 much as possible, the leaves avoid the slitting 

 they would get if they were flat and rigidly inserted 

 on the stalk. Much protection is afforded by 

 stalks standing in close ranks in the field. 



The rain-guard is one of the neatest devices a 

 corn plant can show. It prevents water from 

 getting down between leaf-sheath and stalk. 

 Dirt accumulating there would cause the base of 

 the leaf to rot off. Dirt would injure the ear by 

 getting down between the tender green husks. 

 The guards prevent this. Rain flows down the 

 leaf trough. The stream parts at the guard, runs 

 down the swollen joint of the stalk, and trickles 

 down the outside of the sheath. From one leaf 

 to another it leaps, and waters the roots. Loosen 

 a number of leaves, and study the rain-guard. 

 Study them on the outer husks. Pour or spray 

 an imitation shower on the top of a corn plant, and 

 see the course of the streams as they descend to , 



