264 HOUSE, GARDEN, AND FIELD 



very small, so that it is not easy to make out all the 

 details, but in a flowering grass we can see two things 

 which are peculiar, lightly poised anthers, which hang 

 out and dance in the wind, and long, slender, feathery 

 styles. 



The only plants which come so near to grasses that a 

 doubt can arise as to whether they are grasses or not 

 are certain sedges and rushes. In these the sheathing 

 leaf -bases are either wanting or not split, and there is no 

 colourless scale. The stalks are commonly filled with 

 pith ; the anthers of the stamens are erect, and do not 

 dangle as in grasses. The numbers of the flower-parts 

 are also in many cases different from what we find in 

 grasses, where there are nearly always three stamens and 

 two styles. 



There are many sorts of grasses, and about a hundred 

 species grow wild in the British Isles. A very little atten- 

 tion will show that in every hayfield there are several 

 distinct species with quite different flowers. 



Any grass that we happen to examine will suggest a 

 number of questions, and it may easily happen that among 

 these will be some that we cannot answer to our satisfaction. 

 It is a good practice, however, to put questions incessantly, 

 for it is chiefly in this way that we make progress in the 

 interpretation of natural objects. 



Why are grass-haulms hollow and jointed, that is, with 

 solid partitions at intervals ? A hollow cylinder, like a 

 grass-haulm, is better able to resist bending than a solid 

 stem of the same weight for a given length. Take two 

 lumps of plasticine or modelling clay of the same weight. 

 Shape one into a solid cylinder ; spread out the other into 

 a flat sheet, and roll it up till its edges meet. You can 

 thus get two cylinders of the same length and the same 

 weight, one solid and the other hollow. Lay each upon 

 two supports, the distance between the supports being the 

 same in each case. Then test the power of the two cylinders 

 to resist bending. A tape, holding up a suitable weight, 



