304 ESSAYS ON WHEAT 



succulent and more or less spheroidally swollen at the 

 base. By swelling up in this way, they overcome the 

 resistance of the elastic outer glume and move it out- 

 wards. After a short time the lodicules shrivel up again 

 into small thin scales thus allowing the outer glume to 

 resume its former position and close the flower again. 

 The action of the lodicules in opening the flowers of 

 grasses was first investigated in 1880 by Haeckel, and his 

 observations were confirmed by Rimpau in 1883. When 

 a flower opens, the filaments of the three stamens grow 

 very rapidly in length, and it is this rapid growth which 

 causes the anthers to be pushed out of the flower over 

 the ends of the glumes. This observation was first made 

 by Arkenasy and afterwards confirmed by Rimpau.^^ 



Kerner states that the most favorable conditions for 

 pollination in most Grasses prevail in the early morn- 

 ing, at an hour when there is still some dew lying in the 

 meadows, when the first rays of sunshine fall obliquely 

 upon the flowers, when the temperature is rising gently, 

 and when a light breeze sets the spikes and pannicles in 

 motion. " Under such conditions as these the phenomena 

 of flowering and pollination are accomplished with as- 

 tonishing rapidity. In some Grasses an observer may 

 see the glumes relax and spring open, the stamens grow 

 out, the anthers open, and the pollen scattered, all in the 

 space of a few minutes." ^"^ Wheat is only a glorified 

 grass and although its flowers open early in the morning 

 there are other grasses which, under mid-European con- 

 ditions, open their flowers just as early or even earlier. 

 The time at which the flowers of wheat open relatively 

 to those of other grass species is indicated by Kerner in 



26 p. Knuth, loc. oit., p. 515. 



27 Anton Kerner von Marilaun, The Natural History of Plants, 

 translated by F. W. Oliver, London, Vol. II, 1895, pp. 141-142. 



