14U PHILOSOPHICAL NOTES ON 



ou the leaf from generation to generation, has become a fixed 

 inheritance. 



One cannot stand under a lime-tree in leaf, and look up, 

 without noticing the homology of its branches with decompound 

 leaves. The branches of the lime-tree being horizontal, the 

 identity of the two becomes much more striking. The branch 

 corresponds to the jDetiole and midrib, the secondary branches to 

 the secondary petioles, and so on till we reach the ultimate foliar 

 ex2Jan^^ions, which are the leaves proper ; both in the lime branch 

 and in the decompound leaf the sub-divisions are homologous, 

 althouffh in the latter the ultimate sub-divisions would be called 



o 



leaflets. 



