GRASSES 263 



There is plenty to see at home, and you can make all that 

 you see profitable if you will only form the habit of putting 

 and answering questions for yourself. When you visit a 

 castle set on a ridge, such as Belvoir, Richmond, Beeston 

 or Bamborough, ask yourself how the ridge comes to be 

 there. When you visit the Roman wall, look out for 

 the natural feature which determined the choice of that 

 particular line, and possibly gave the first hint that a 

 fortification might be easily made there and easily defended. 

 Do not sterilise your geological or natural history rambles 

 by mechanical occupations, such as aimless collecting, or 

 the writing out of lists of species. Half a dozen questions 

 answered nay, half a dozen questions attempted may 

 be more to the purpose than note-books crowded with un- 

 productive facts. 



XLVII. GRASSES. 



The characters of grasses. By what marks do we recognise 

 grasses ? I suppose that most of us would say that any 

 plant is a grass which has long, narrow, pointed leaves, 

 hollow stalks (haulms), and small, greenish flowers. So 

 different are grasses from all other plants that we should 

 have no hesitation in deciding whether a single leaf, a 

 single haulm or a little cluster of flowers belonged to a 

 grass or not. When we look closely it is easy to find 

 further differences between grasses and other plants. 

 The base of a grass-leaf forms a sheath around the haulm, 

 which runs down the stem to the knot next below, and is 

 nearly always split. Just at the place where the blade 

 becomes free, there is a little colourless scale, which is in 

 close contact with the haulm. The leaf is generally ridged 

 on its upper surface, and if we cut it across and look at 

 the cut edge with a lens, angular ridges will be seen. The 

 hollow haulm, with knots at intervals, is almost equally 

 distinctive. The flowers are usually very numerous and 



