128 ROUND THE YEAR 



stalk appears at all, it is of later formation than the 

 base and blade, and appears between them. In the 

 rudimentary leaf of the bud -scale of Sycamore no 

 leaf-stalk forms because the development of the leaf 

 is checked in an early stage. Hence the bud-scale 

 itself is not properly, in the Sycamore, a leaf-stalk, but 

 a greatly enlarged leaf-base. 



By close examination we can satisfy ourselves that 

 the bud-scales of the Beech are not leaf-bases, as in 

 the Sycamore, but stipules. Between each pair there 

 is a minute green leaf, which never develops. The 

 bud-scales are the stipules of several such undeveloped 

 leaves. 1 



The bud of Lilac exhibits some interesting pecu- 

 liarities. Here the branch does not usually end in a 

 single bud, as in most trees, but the terminal bud fails 

 to develop, and a pair of lateral buds take its place ; 

 hence the strong tendency to fork which we find in 

 the branches of Lilac. The central leaves are en- 

 veloped in four rows of bud-scales, alternately two 

 or three in a row. So far there is nothing out of the 

 common. But if you dissect away the bud-scales 

 and examine them one by one, you will find that 

 they pass by insensible gradations into ordinary 

 foliage-leaves. The outermost scales are triangular, 

 the next longer and narrower at the base, and so on. 

 There are no rudiments of blades at the tips. The 

 bud-scales are not here enlarged leaf-bases, but small 

 leaves, the blade being more and more developed as 

 we pass inwards. 



Bud-scales are not therefore all formed exactly in 

 1 Goebel, Bot. Zeitimg, p. 774 (1880). 



