ANATOMY OF THE JULIANIACEZX. 135 
compartments by relatively thin septa. The basal portions are much thickened and 
swollen, and are sunk in amongst the surrounding epidermal cells, which show a more or 
less distinct radial arrangement ; the sunken base of the hair not rarely projects a short 
distance into the subjacent mesophyll. The cuticle of the surrounding epidermal cells 
is slightly raised to form a kind of collar around the base of the hair (fig. 1, A), and this 
collar is apparently not continuous with the cuticle of the upper part of the hair. 
Below this point the trichome is sometimes slightly narrowed before expanding into the 
swollen basal portion. The wall of the hair bears simple slit-shaped pits, which are most 
prominently developed in the lower part (not figured). Towards the pointed apex the lumen 
of the hair often disappears entirely and the hair becomes solid. Curved trichomes are 
characteristic of J. adstringens and are occasionally found also in J. amplifolia ; they 
have rather thinner walls than the straight hairs just described and have a more or less 
undulated outline ; otherwise they agree in structure with the hairs of J. amplifolia and 
J. mollis. . The trichomes of Orihopterygium, as above mentioned, are prevalently 
bicellular and occasionally unicellular. They are, on the whole, far shorter than the 
type of hair found in Jwliania, and do not run out to such a sharp point; they are 
rarely straight, more commonly curved towards the one side or other (fig. 1, D), and the 
walls are relatively thin. There is no well-marked cuticular collar, and the sunken 
base of the hair is very little swollen. The base of the hair is invariably provided with 
simple pits (not tigured), the latter sometimes also occurring on the wall of the projecting 
portion of the trichome. Another point of difference between Juliania and Ortho- 
pterygium lies in the distribution of the hairs; in the former genus they are practically 
confined to the veins (even in the very hairy J. mollis), while in Orthopterygium they 
are distributed fairly uniformly over the surface of the leaf. 
In amongst the clothing-hairs the glands (cf. fig. 1, p. 136) are scattered. These 
glandular hairs are found in all the members of the Order and in about equal abundance, 
and although they show a certain amount of diversity there is a general ground-plan 
underlying their structure, which makes them an important character for the diagnosis 
of the Order. They are found in about equal numbers on both surfaces of the leaf and 
occur uniformly distributed all over the epidermis. In appearance these glands are 
very much like those of some Anacardiacez, e. g. Dobinea*. They are always 
provided with a stalk composed of a single row of one or two, more or less elongated 
cells; upon this the actual body of the gland is borne. The stalk of the glands is 
directly attached to a single epidermal cell and is in no way sunk, as is the case with 
the base of the clothing-hairs (fig. 1, A, B); the epidermal cells surrounding the one 
from which a gland arises sometimes exhibit a more or less distinct radial arrangement. 
The body of the gland is very commonly not a straight continuation of the stalk, but is 
more or less curved—frequently so much so that the apex comes to lie in close proximity 
to the stalk (fig. 1, E, F). Asa rule, the gland proper is of somewhat larger diameter 
than the stalk; it consists of a number of short, flat cells, which frequently exhibit 
further subdivision by vertical walls, . e., the glands have a multicellular head with 
horizontal and vertical division-walls. In many cases the secretion was still well 
* Cf. Solereder, ‘Systematische Anatomie der Dicotyledonen,’ 1899, pp. 278, 279. 
