OF BACCHARIS GENISTELLOIDES 689 
It is difficult to determine the function of either kind of hairs, 
if they have any. In the younger parts, where alone the hairs are 
plentiful, they are often entirely embedded in the wax. The gland- 
cells are usually thickly covered, while occasionally part of the 
end-cell of the whip-hair protrudes beyond. Of what use can a 
secretion be, the escape of which is entirely prevented? In the 
cases among the Compositae in which the whip-hairs are found, 
they are usually present as Vesque shows as a tomentum, Prob- 
ably here, as in Chrysoma pauciflosculosa described by Professor 
Lloyd, they are functionless.* 
The stomata are evidently of a motile type (f 7). They are 
provided with distinct accessory cells, so that this plant adds 
another to the list of composites so_pro- 
vided, although Benecke + declares these {BA Yai 
cases rare. Both upper and lower walls bo: 
taper into very finely pointed ridges. No 
trace of a hinge has been discovered by me, 
but the cutin seems thinner at the junction 
of the guard and accessory cell. The accessory cells raise the 
stomata somewhat above the level of the epidermis. They are 
more exserted on the stem than on the wing. 
Fic. 7. Stoma from 
stem of Baccharis geni- 
stelloides, 
THE STEM 
In the plants examined, the stem varies in thickness from I to 4 
mm. In the younger portions, to about 12 cm. from the tip, the 
supporting tissue consists largely of sclerenchyma, the wood proper 
being confined to a very narrow ring about 25 in diameter. 
The masses of bast-fibers are found at intervals around the stem, 
but the six largest masses are opposite the three wings and half way 
between them respectively (/ 8). These bast-fibers are strongly 
lignified, so that they give a much more pronounced reaction with 
phloroglucin than the young wood-ring itself. The lignification 
of the bast-fibers begins very near the growing tip ; signs of it 
can be found at the distance of 1.5 cm. therefrom. This early 
acquisition of lignin would seem to indicate a very slow rate of 
growth —a point which will be recurred to presently. 
Pai 
* Lloyd, F. E. Anatomy of Chrysoma pauctflosculosa. 
445. Au Igor. 
} Bot. Zeit. 50: 570. 1892. 
Bull. Torrey Club, 28: 
