570 TitAXSACTIONS AND TKOCEEDINGS OF THE [Sess. lvii. 



The first one or two pluiiiular leaves are, in typical 

 seedlings, provided with a simple spathulate or elliptical 

 lamina without a terminal spine, supported on a somewhat 

 elongated petiole-like structure (flattened vertically from 

 above downwards), which passes gradually over into the 

 lamina at its apex, while its base expands into a small 

 sheath without stipules. These leaves are seldom 

 expanded in a flat and horizontal manner, but the lateral 

 margins generally curve upwards, so as to make the upper 

 surface take the form of a more or less narrow longitudinal 

 groove, which is continued down the upper face of the flat 

 petiole to the sheathing base. 



The upper surface is generally glabrous, like that of 

 the cotyledons, but the lower is, on the other hand, 

 covered with long white hairs, as are also the edges. The 

 second or third leaf, according as the first one or two are 

 simple, is generally provided with a small lateral leaflet, 

 placed on one side of the main leaf, at or near the junction 

 of the lamina with the petiole. This lateral leaflet exactly 

 I'eproduces the lamina of the terminal part, but is much 

 smaller in size, and the whole does not difler from those 

 already described, except by the presence of this lateral 

 appendage. After the appearance of one or two of these 

 transition forms, the leaf, generally the fifth, sixth, or 

 seventh, is found to have an additional lateral leaflet placed 

 on the opposite side, so that it is now a tripartite leaf, 

 all the segments being of nearly the same size. 



The leaflets are now quite covered with long soft hairs, 

 even on the upper surface, which had hitherto remained 

 smooth, and tlie hairs on the leaf margins are especially 

 long. 



A considerable number of leaves are of this tripartite form, 

 and usually it extends as far as the tenth, twelfth, or even 

 thirteentli leaf, the leaflets Ijecoming gradually narrower in 

 the higher leaves. Thereafter the lateral lobes begin to 

 diminish in size, and finally one disappears leaving a long, 

 linear, median part, the lamina of which is but slightly 

 broader than the petiole, and terminates in a short soft 

 spine, together witli a small, almost linear, lateral lobe on 

 one side. 



This lateral structure disappears in the succeeding one 



