THE COMPOUND LEAF 87 



marked difference between the distinct divisions in 

 the Virgiaia creeper and the ill-defined ones in 

 grape and Canada thistle, we may give the two 

 types different names. Or, the parts of a com- 

 pound leaf are leaflets ; the deep cut parts, like 

 those in the thistle', are divisions or segments; the 

 shallower parts ( ordinal'!] y not extending more than 

 half way to the midrib) are lobes, as in Fig. 

 81. 



Suggestions. — The pupil will now find himself applying the fore- 

 going tests to all the leaves which he meets. Let him determine 

 whether any plant bears both simple and compound leaves. He may 

 be interested in examining the so-called Boston ivy or Japanese Vir- 

 ginia creeper which is much planted for covering houses; also, the 

 horse-radish (examine the very earliest leaves in spring) ; also, one of 

 the cultivated forsythias or yellow bells (the so-called climbing one, 

 Forsythia suspensa). 



XVII. THE COMPOUND LEAF 



94. The leaflets of the dewberry and Virginia 

 creeper arise from a common point, — the top of 

 the petiole. If the blade of the thistle (Fig. 83) 

 were compound, the leaflets would evidently be 

 distributed in two rows along a central axis. 

 Compare Figs. 84 and 85. There are, then, 

 two distinct types of compound leaves,— the digi- 

 tate or palmate (in which the leaflets are at- 



