LEAVES. 93 



That a compound leaf, in spite of the joints of the separate 

 leaflets, is really only one leaf, is shown : (1) by the absence 

 of buds in the axils of leaflets ; (2) by the arrangement of the 

 blades of the leaflets horizontally, without any twist in their 

 individual leafstalks ; (3) by the fact that their arrangement 



Fig. 76. — Pinnately Compound Leaf of Locust, with Spines for Stipules. 



on the midrib does not follow any of the systems of leaf 

 arrangement on ttie stem (§ 122). If each leaflet of a com- 

 pound leaf should itself become compound, the result would 

 be to produce a twice compound leaf. Fig. 85 shows that of 

 an acacia. 



