I could not imagine what had formed this wood, and it remained a complete puzzle to me until the following spring, when I found in the expanding shoots, that, wherever a flower-cluster was present, there were one or two pairs of leaflets already well developed in the axils, and that the next season's buds were forming between them, while the internodes of these leaflets were making quite a rapid growth.

Polyzoary divided into distinct internodes by flexible articulations.

The cells are placed in pairs, but one is always a little higher than the other (subalternate) and one pair is placed on each internode on the pinnae.

Large-leaved trees have longer internodes than those with small leaves.]