IN THE MEADOW 45 



near the fastened end. Why must the trunk of a tree be 

 strongest near the ground ? Why is a crowbar strongest 

 near the lower end? The culms are strengthened still more 

 by several other devices, two of which we can easily under- 

 stand. You notice that the culms have knots, or nodes, at 

 intervals, that these nodes are solid and hard, and that they 

 are closest together near the ground. The leaves all sur- 

 round the culm like a sheath for a part of their length. 

 These sheaths strengthen the culm in the weak points just 

 above the nodes. Strip off the leaf sheaths and prove that 

 there are weak points just above the nodes. The holloiv 

 culms thus strengthened admirably combine strength with light- 

 ness and, as we all know, are not easily kneed or broken be- 

 fore the seeds are ripe. What change takes place in the 

 strength of the culms after the seeds are ripe ? Does ripe 

 grain show boldly upright ears and culms ? 



Grass culms do not branch ; their leaves are almost or en- 

 tirely linear in shape and have parallel veins. Show how 

 grasses are enabled to grow so close together. How many 

 stalks can you count in a square yard of meadow ? 



Perhaps it has never occurred to you that grasses have 

 flowers; but what we call ears or heads are really their 

 flowers. None of them, it is true, have a distinct calyx and 

 corolla ; still, if we look just at the right time, we can easily 

 find the tiny stamens with anthers hanging out of the little 

 chaff-like scales. The pistils often end in delicate little 

 feathers. You must try to find both. The heads of grasses 

 make very pretty bouquets, which last a long time, and need 

 not be put in water. We shall see how many pretty bou- 

 quets we can collect. 



We have spoken several times about insects fertilizing 

 flowers which attract them by their bright colors and by 



Look for plants of the golden rod, wild sunflower, rosin-weed, blazing 

 star, wild aster, garden aster, dahlia, dandelion, and other composites. 



