HEDGE AND DITCH 159 



between such prickles as these and the thorns of hawthorn. 

 Point out also any difference in function. 



Cleavers. A third hook-climber of the hedge is cleavers 

 or goose-grass. Its hooks are so minute that you do not 

 see them at all without a lens. Yet you know how it 

 clings to clothes, and you see that it can cling to leaves 

 and stalks in the same way. Draw some of the hooks 

 with a microscope or lens, and see if you can discover any 

 purpose besides climbing to which they are put by this 

 plant. How does cleavers disperse its fruits ? 



Ivy. There is no ivy in the hedge, but plenty on old 

 walls in the village. How does ivy climb ? Bring speci- 

 mens to prove what you say. Why do the tips of the 

 leaves of climbing ivy always point downwards ? (8) How 

 do the flowering and fruiting branches differ from the 

 climbing stem ? 



Clematis. If we lived in one of the southern counties 

 of England, and particularly if we lived on a chalky soil, 

 we should find the clematis or traveller's joy growing 

 freely in our hedges. But it is not seen in Yorkshire ex- 

 cept where planted. If you have an opportunity of 

 examining this or any clematis of the gardens, observe 

 how it grasps its support. The leaf -stalk is sensitive to 

 contact on its under surface, and curls round any fixed 

 object which is not too large ; then it thickens and stiffens 

 along the curved part, and at last becomes immoveably 

 fixed. The Tropseolum of our gardens climbs in the same 

 fashion. 



Bryony. The real bryony of our hedges, often called 

 red bryony, has a method of climbing different from all the 

 climbers which have been mentioned hitherto. It sends 

 out a long slender tendril, which grasps a twig, and then 

 contracts into a close-wound coil, dragging the stem nearer 

 to its support, and securing it firmly, though with a certain 

 amount of free play, which is useful in a gale of wind. 

 Observe an unattached tendril ; and see how it reaches 

 out for something to cling to ; its tip is curled, but it is 



