GRASSES 269 



of water cannot pass into narrow spaces bounded by 

 un wet table surfaces, so that a scale does not seem to be 

 necessary to hinder it from passing in here. I took three 

 common grasses, cut off the leaf -blades and their scales 

 (ligules), and immersed them in water ; no water made its 

 way into the leaf-sheaths. The scale is very constant in 

 true grasses, and peculiar to them. 



Why do the anthers of grass flowers dangle ? In order that 

 the wind may shake the pollen out of them more easily. 

 In hay-time the air carries everywhere the minute pollen- 

 grains of grasses, and at this season the dust which settles 

 in still places always contains grass-pollen. Grasses are 

 wind-pollinated. 



Why are the styles of grass-flowers long and feathered ? 

 In order that they may have a better chance of catching 

 some of the pollen-grains which are wafted past by the 

 wind. 



Why are grass-flowers small, inconspicuous and greenish? 

 Because the grass has no need of insects or other animals 

 to pollinate its stigmas. 



Remark the differences between a flower which is wind- 

 pollinated and one which is insect-pollinated. We may 

 take any common grass as an example of the first kind. 

 Red clover, primrose, convolvulus, rhododendron and 

 orchids are familiar examples of the other kind. 



Wind-pollinated flowers Jnsect-pollinated flowers 



(1) are inconspicuous, 



(2) are scentless, 



(3) secrete no honey, 



(4) produce much pollen, most 



of it being wasted, 



(1) are usually conspicuous, 



(2) are often scented, 



(3) usually secrete honey, 



(4) produce less pollen, com- 



paratively little being 



(5) often have feathered wasted, 



stigmas. i (5) usually have simple stigmas. 



In certain states of the weather grass-leaves exude much 

 water. There are fissures in them, by which drops of 

 water can be passed out. It seems that a low temperature 



