STUDY OF A FAMILIAR PLANT 



upward . But it is not very strong, and when it is a few inches 

 in length its weight and that of the leaves make it bend over ; 

 from this time on, unless care is taken to train it upward on 

 a trellis or other support, the stem sprawls on the surface of 

 the ground. 



6. Leaves. The secondary leaves (a name given to all 

 the leaves that are formed after the two seed leaves) are pro- 

 duced at intervals along the stem. They are alternately 

 arranged that is, at one point on the stem only one leaf 

 arises, and the leaf 

 next above will be 

 not on the same side 

 but on a different side 

 of the stem. Each 

 leaf has two parts, 

 the leaf-stalk and the 

 blade (Fig. 3). The 

 blade is the large, flat 

 portion of the leaf. 

 It has a lobed outline, 

 the three or five lobes 

 being pointed, and 

 the edge of each lobe 

 irregularly toothed. 

 There are many hairs growing on both the upper and lower 

 surfaces of the leaf, as well as on the leaf -stalk and on the 

 stem and branches of the plant. If the leaf be held up 

 between the eye and a window, one can see in the blade 

 many light green lines, the veins. Five large veins spread out 

 from the point where the blade is attached to the leaf -stalk ; 

 as these main veins spread out in the blade they give off 

 branches, the branches branch, and so on until the whole 

 system of veins looks like a network. It is in the leaf that 

 much of the food is manufactured which is to be used in the 

 growth of the plant, and the veins are useful in two ways : 



FIG. 3. Portion of a cucumber stem bearing 

 a leaf and a tendril. 



