84 NATURE TEACHING 



bud. These points can be readily made out by cutting 

 onions both across and lengthwise. Make similar obser- 

 vations on a hyacinth bulb, and compare the two care- 

 fully. 



Examine, in the hedges, shoots of traveller's-joy 

 (common only on chalk and limestone districts), and see 

 how it climbs by twisting its long leaf stalks around 

 twigs of other plants. In addition or in place of the 

 traveller's-joy, look at garden nasturtiums, and see how 

 these support themselves in much the same way. 

 Make a sketch of a nasturtium holding on to a stick or 

 other support. Examine the garden pea, sweet pea, or 

 wild vetches. In all these plants the end of the leaf is 

 prolonged into a special climbing organ, a tendril, which 

 can wrap round a stick or string, and so hold the plant 

 up. Compare young leaves which have not as yet 

 caught hold of a support and older ones which have. 

 Sketch one of each. 



Structure of Leaves. 



Observe the veins of the leaves under examination. 

 See how much firmer they are than the rest of the leaf; 

 how they support the softer tissue. Hunt among decay- 

 ing leaves in wet places under trees, and try to find some 

 " skeleton " leaves in which the soft parts having rotted, 

 the hard and more resistent veins remain as a skeleton 

 of the leaf. 



Take some box leaves and boil them for fifteen 

 minutes in water to which caustic potash has been added, 

 in about the proportion of -fa oz. of the potash to i oz. 

 of water. After boiling, pour away the potash and put 



