76 THE OAK 
These scars of the stipular bud-scales, like those of fallen 
leaves, exhibit the points of rupture of the vascular 
bundles which ran across from the bundles of the bud- 
axis. It only remains to point out that the buds vary 
in size and vigour according to the age and condition 
of the tree; the buds on oaks less than fifty years old 
very rarely have inflorescences developed in them, and 
I shall defer the consideration of these till we come to 
the flower. 
The mature leaf of the oak (fig. 20) is obovate in 
eeneral outline, with rather deep sinuses cutting the 
margin on each side into about six or eight rounded lobes; 
the apex is rounded or blunt, and some variation occurs 
in the degree of incision between the lobes. The base 
either tapers slightly into an evident petiole, or it is pro- 
longed on either side of a very short petiole so as to form 
small auricles. In the commonest variety the margins 
and surfaces of the leaf are quite smooth, but the race- 
form known as Quercus sessiliflora has the young leaves 
pubescent beneath. 
The venation consists of a midrib running from base 
to apex, and pinnate lateral ribs running from the 
midrib at an angle of about 45° to the tip of each lobe, 
the points of origin being alternate or nearly opposite, 
and the angle referred to subtending forwards. These 
principal ribs are prominent below but not at all so 
above. ‘I'he leaf-tissue (mesophyll) between these is 
permeated by numerous smaller vascular bundles 
united into an irregular network, but so arranged that 
