174 GROWTH AND WORK OF PLANTS 



their length. The filament is attached to the side of one end of 

 this connective. Each locule of the anther is grooved on its 

 outer face, so that it appears to be made up of two lobes, but 

 there is really only one. At the time of flowering the filaments 

 elongate and lift the anthers far out of the flower. The fila- 

 ments being slender and delicate are bent over by the weight of 

 the anther, which dangles here and is easily agitated by the wind. 

 The anther sacs open on the outer side of the free end. A split 

 occurs in the wall along the groove for a short distance and the 

 walls bend backward so that a nearly circular pore is formed. 

 The pollen grains are nearly spherical, smooth, and quite firm. 

 As the anther dangles at the end of the filament, a light jar, 

 which even a slight breeze would give it, sets the pollen grains 

 rolling out of the opening. They usually fall out in large num- 

 bers. They may fall directly on the silk of the ear of the same 

 stalk, or, as is more often the case, the wind carries them to the 

 silk of adjacent plants. The blades of corn, and the ground of 

 a field, are often literally covered with pollen grains, so great is 

 the number. 



279. The sterile flower. The sterile flower, the one with 

 imperfect or no stamens, lies between the palet of the fertile 

 flower and the other large empty glume which covers the sterile 

 flower. If care is used in dissecting the sterile flower by spread- 

 ing it apart, two membranous bracts will be found. They are 

 somewhat shorter and narrower than the others. The one 

 lying next the empty glume is the flowering glume, while the 

 other is the palet, and it lies next the palet of the fertile flower. 

 Between these two membranous bracts, i.e., between the palet 

 and flowering glume of the sterile flower, may often be found 

 remnants of the stamens, sometimes rudiments only in the form 

 of slender threads, two or three of them. At other times fila- 

 ments and anthers are both formed, but the pollen is unformed 

 and imperfect. In many such cases the filament does not elon- 

 gate and the anthers do not emerge from the closed flower. In 

 a few cases the stamens are perfect and well formed. Such a 

 spikelet contains two fertile flowers. 



