136 



FOUNDATIONS OF BOTANY 



bristle-shaped objects at the base of the leaf, as in the 

 apple leaf (Fig. 98), sometimes as leaf-like bodies, for 

 example in the pansy (Fig. 99), and in 

 many other forms, one of which is that 

 of spinous appendages, as shown in the 

 common locust (Fig. 103). 



145. Parallel -Veined Leaves. The 

 leaves of many great groups of plants, 

 such as the lilies, the sedges, and the 

 grasses, are commonly parallel-veined, 

 that is, with the veins running nearly 

 parallel, lengthwise through the blade, 



PIG. 100. Parallel- 

 Veined Leaf of Sol- as shown in Fig. 100, or 



with parallel veins pro- 

 ceeding from a midrib and thence extend- 

 ing to the margin, as shown in Fig. 101. 



146. Occurrence of Netted Veining and 

 of Parallel Veining. The student has 

 already, in his experiments on germina- 

 tion, had an opportunity to observe the 

 difference in mode of veining between 

 the leaves of some dicotyledonous plants 

 and those of monocotyledonous plants. 

 This difference is general throughout 

 these great groups of flowering plants. 

 What is the difference? 



The polycotyledonous pines, spruces, no. 101. - Parallel 

 and other coniferous trees have leaves verunniSom 

 with but a single vein, or two or three midrib to margin< 

 parallel ones, but in their case the veining could hardly 

 be other than parallel, since the needle-like leaves are so 



