NOTES ON BUDS 
9 
as is usual with most plants, as horse-chestnut, rose, laburnum 
(fig. 8), & c., are “ conduplicate,” i.e., the two halves of the blade 
are folded tightly together, like a sheet of note paper. 1 his 
protects the upper surfaces, while an additional advantage is 
gained by the blades being placed at first vertically. As the 
pairs of leaflets are developed they open out and become hori- 
zontal, one pair after another, until the whole leaf is mature. 
In the ash the dark brown buds consist of petiolar scales, 
and if examined in spring, they afford an excellent illustration 
of transitions between petiolar scales and true leaves. Instead 
of curving downwards on expansion, as in the walnut, the 
petioles are erect, but this still enables the undeveloped leaves 
to stand in a vertical plane. 
Horse Chestnut. 
Fig. 2. 
Lupi nus pilostts. 
Leaf, seen la- 
terally, asleep at 
night-time. 
After Darwin. 
Fig. 3. 
Walnut. 
In the winter, however, on dissecting a bud after removing 
the scales, a pellet of dark brown wool is seen, and on teazing 
this out, little white leaves will be found on which the wool 
grows. The hairs are filled with pale brown liquid and 
granules. 
Stipular Scales. — Many plants are provided with a pair of 
small appendages at the base of the leaf. These are called 
“ stipules,” and the leaf is said to be “ stipulate.” Those 
hitherto described had none and are, therefore, “ ex-stipulate.” 
Now what are “stipules”? They represent a basal pair of 
leaflets in compound leaves, and detached basal portions of 
a single leaf ; but instead of growing out of the petiole as 
leaflets, as, indeed, some stipules do, such as those of the rose ; 
(though the stipules having the new function of protecting the 
bud in the “ axil ” they do not assume the form of leaflets in the 
rose) stipules usually arise directly from the stem, the connection 
with the petiole of the leaf being concealed within the stem itself. The 
rule is that three, five or more “ fibro-vascular cords” pass out 
of the cylinder of wood within the stem and enter the petiole of 
the leaf. Then, secondary cords branch off from the two lateral petiolar 
cords and enter the stipules. If there be two opposite leaves, 
then two horizontal cords run round the stem from the one leaf to 
the other, forming a “stipular fibro-vascular zone.” From this 
arise the cords which enter the stipules. This is well and 
