264 MR. PERCY GROOM ON BUD-PROTECTION ІХ DICOTYLEDONS. 
contain a younger leaf, whilst the unoccupied space is filled with secretion. This 
enelosed leaf contains in its sheathing base younger leaves, and finally the growing- 
point. The young leaf arises in the form of an annular outgrowth surrounding the 
growing-point. This ring is more developed on the side which produees the lamina. 
Тһе ring expands later into the “sheath.” Тһе oldest enclosed leaf pushes through the 
slit at the top of the sheath surrounding it, and by its growth ruptures the latter down 
to its very base. Тһе emerging leaf is coated with secretion and is brown in tint; the 
brown tint is due largely (solely ?) to the presence of tannin. 
The secretion is poured out by the epidermis of the young leaf and by a few capitate 
hairs. It is worthy of note that there is an internal secretory apparatus producing resin 
and mucilage. Тһе internal secreting-cells arise very early and are seen in very young 
leaves and high up the growing-point. ' 
Conclusions concerning Colleters. 
1. Villous colleters are frequently emergences; they are emergences in their mode of 
origin. Frequently, too, their emergence nature is made clear by reason of the 
fact that laticiferous tubes or vascular bundles penetrate them. 
2. They are formed for the sake of the bud, being protective, also probably excretory, in 
funetion. 
3. Mode of secretion іп Gardenia florida. 
(1.) Seeretion commences very early indeed in each cell. 
(ii. The mucilage (mucigen ?) arises in the form of droplets in the cell-protoplasm. 
(iii) There are traces of a difference between the secretion inside the cell and that 
outside the cellulose wall. x 
(iv.) Resin occurs inside the secreting-cells. 
4. The secretion in part passes through the cuticle in some plants at any rate (4lla- 
manda). 
5. There never was a trace of the formation of two cuticles in the plants observed. 
6. Contents of the Villi—Food is conveyed to the secretory cells in a carbohydrate form, 
for transitory starch occurs in the conducting parenchyma of the colleter. Іп 
addition raphides or sphero-crystals, colouring-matters, and tannin are found in 
villi. 
7. It is significant that laticiferous tubes, containing substances identical with those 
normally found and even secreted by the villi, pass into the colleters. 
I take the opportunity of thanking Mr. Walter Gardiner, F.R.S., for his constant 
help throughout the progress of the work. Indeed, were it not that he would be. 
rendered responsible for all the statements and views expressed in this paper, his name 
would be fitly on the titlepage. I desire also to express my thanks to Mr. M. C. Potter 
for material of Gardenia laurifolia and Tabernemontana dichotoma, and for a figure of 
the former. 
