52 ETON NATURE-STUDY 



(3) Discover why the leaf so easily came away, and write the 

 reason under a special heading. 



(4) Mention : Give : Leave : 



Any special structure A diagram A space for a 



near the leaf scar sketch 



By removing other leaves (if necessary first cutting away part of 

 their bases) endeavour to find out what it is that holds the leaf uutil 

 the last moment. 



Take a shoot of Tropaeolum (common " Nas- 

 turtium ") which has been soaked in hot water. Look 

 at the big veins in one of its leaves, hold the stalk to 

 the light, and trace the continuation of the veins 

 right down until they join with similar cords in 

 the stem itself. Write down what you have 

 done, and sketch the two connections you have FIGURE 47. 



traced. 



Find out how many rows of leaves there are on a sycamore twig. 

 Draw three or four circles, one within the other, each of which is to 

 represent one of the nodes or parts of the stem from which the leaves 

 grow (see figure 47). Mark on each circle the relative position of 

 the leaves. Dra\v two diameters at right angles, joining all the 

 leaves, and note how much of a circle lies between each leaf and its 

 neighbours in the next rows. 



SUGGESTIONS FOR FURTHER WORK IN SCHOOL 

 Study other twigs such as Elm, Birch and Broom, on which there 

 are different numbers of leaf rows. 



SUGGESTIONS FOR FURTHER WORK OUT OF SCHOOL 

 See Chapters V and XIV. 



