84 THE BRACTS AND FLOWERS. 



and one glume, when I could not expect any of my readers to 

 see more than one flower with three glumes. 



After carefully examining a great variety of genera, and com- 

 paring them with the nearest allied orders, it appeared to me 

 that no distinct and universally applicable definition of the term 

 glume could be given unless it were applied, as in Cyperaceae, to 

 the whole of the primary scales attached to the main axis of the 

 spikelet. After printing, I ascertained that similar views had 

 been independently propounded by Hugo, Mohl, Doll and others 

 in Germany, and by Germain de St. Pierre, in France. 



In several of our large genera of grasses, the only difference 

 between the one or two outer empty glumes and the flowering 

 ones is that they are rather smaller or rather larger, and there is 

 often more difference between the first and second empty glumes 

 than between the upper empty glume and the first flowering one. 

 In couch grass the empty and flowering glumes are precisely 

 similar, very gradually diminishing in size from the outer empty 

 to the uppermost flowering glume. An empty glume in one 

 spikelet may correspond to a flowering one in another spikelet of 

 the same plant. In rye-grass the spikelets are alternately placed 

 in one plane, right and left, the single empty glume of each 

 spikelet being the lowest and outer one, whilst the second glume 

 next the axis of inflorescence, is the lowest flowering one. In the 

 uppermost spikelet there are two empty glumes, aiid this is not 

 owing to the development of an additional outer glume, for the 

 lower of the two empty ones is on the side it ought to be in the 

 regular alternation with the lower spikelets , but the second 

 glume, which in the lower spikelets encloses a flower, 13 in this 

 subterminal one empty. So in several Paniceae, the second or 

 third glume, according to the genus or species, has been observed 

 sometimes, to enclose a rudimentary or male, or even a perfect 

 flower, and at other times to be quite empty, without any change 

 in its appearance. 



