46 CHANDLER—DONATIA NOVAE-ZELANDIAE. 
in the centre of the bundle is well marked, as is the phloem which 
surrounds it. Mucilage cells are abundant. 
Similar appearances to the foregoing are found from the base 
of the leaf to about the centre, where the single median nerve 
divides, giving off two side veins, and thus a section across the 
centre of the leaf shows three vascular bundles (Fig. 7). The 
leaf is now more symmetrical in shape, losing its triangular form 
and becoming somewhat oval. The cells of the mesophyll are 
large and regular. The bundles are similar to the median nerve 
in the basal section, but, on the outer side of each bundle, scler- 
enchyma is developed. Stomata are occasionally found, and 
mucilage cells are more abundant. As might be expected from 
the habit of growth, the tips of the leaves differ considerably 
in structure from the basal and central portions (Fig. 8). This 
‘is the exposed part of the leaf, and stomata are very abundant. 
Passing upwards to the tip of the leaf, the cuticle becomes lighter 
in colour and very thick, the mesophyll is differentiated into 
long, palisade cells under the epiderntis and loosely-arranged 
cells towards the centre of the section, first occupied by three 
vascular bundles, but later by one, as the tip of the leaf is reached. 
There is a large amount of = developed on the 
outside of the bundle. 
Fumago Donatiae, Chandler. 
An Epiphytic Fungus occurring on Donatia novae-zelandiae, 
Descr.—Effusa hyphis late racemosis; cellulis brevibus 
crassis ; conidiis catenulatis, sphaericis v. sphaerico- 
cuboideis; hyphis fertilibus raris; sed crebro fila- 
mentis conjugatis. 
Hab.—Inter pilos circa caulem Donatiae novae-zelandiae. 
Intermingled with the hairs of Donatia novae-zelandiae is 
found the mycelium of a fungus. The fungus is epiphytic, for 
its mycelium merely twines in and out among the hairs of the 
stem, and lies on the epidermis, not actually piercing the tissue 
(Figs. 5 and 9). The filaments of the mycelium consist of thick- 
walled cells of an intense brown colour (Figs. 5 and 10), and they 
branch freely—the young branches being delicate and colourless, 
Bead-like gonidia are found on the mycelium (Fig. roa). We 
know from De Bary * that a resting mycelium stage and resting 
gonidia are common in starved specimens of Fumago, Penicillium, 
and Pleospora. In this and other characters the fungus on 
Donatia resembles species of Fumago, the soot-fungus. 
* De Bary, Comp. Morp. and Biol, of the Fungi, Mycetozoa, and Bacteria, 
