4(i4 WILL 18 : MOHPHOLOLY OF THE PODü8'I'BMACEÆ 
section of growin” margin of thallns, X 320, showing meristem and root- 
cap. 0'.6'.). 3 A young plant in May, nat. size ; the primary axis ; 
S.S., the secondary shoots ; th., the thallus. 4 Slightly diagrammatic 
reproduction of the original drawing of Podostemon G-ardneri (the 
primary axis. with its brush of leaves), with the addition of part of 
the thallus, and with two secondary shoots ; gathered in August ; nat. 
size. 5 Transverse section of thallus, x 320, showing epidermis (<9^?.), 
parenchymatous cortex Cp.c.), and a vascular strand (f.b.'). 6 Portion of 
thallus, X li, showing stages in the transformation of vegetative into 
floral shoots by the enlargement of the bases o f the now prostrate leaves 
and the fall of their tips. 
Plate XXXV., Hydrohryum olivaceum zeylanicum, a plant in 
vegetative condition, gathered in August, X 4/5.— This shows the habit 
particularly well, but it should be noted that most of the leaves, both of 
the primary shoot and the secondaries, have fallen off, owing to the 
specimen having been kept in standing water for some time. If photo- 
graphed in the perfectly fresh condition, the thallus would be completely 
hidden by the leaves, except at the margins. The primary axis is visible 
at the lower side of the picture, and the mode of branching of the thallu 
is clearly seen. The photograph shows, what is not visible to the eye, the 
actual overlapping of the lobes in one or two places. The younger leaves 
of the secondary shoots near the margins can be seen emerging from the 
thallus, 
Plate XXXVI., Hydrohryum olivaceum zeylanicum (figs, 1-5).— 1 
Secondary shoot, X 4, the flower just about to emerge from the spathe 
(.çj^.), which has split along the upper side. 2 Open flower, from the side, 
X 4. 3 Piece of rejuvenescent thallus, developing from an old portion 
which has been re-submerged, X 7. At an the first sign of appearance of 
the secondary shoot ; .s*. .9., an older shoot. 4 Rejuvenescence from the side, 
X 7. 5 A monstrous thallus, described at p, 391 ; the primary axis 
bent down 
H. Griffithii (figs. 6-8). — 6 Portion of thallus, near a sinus, with 
secondary shoot in floral condition at the angle, X 4. 7 Ovary and stigmas 
from side, X 4|. 8 Stigmas of various flowers from same locality, X 8, to 
show variety of form {of. PL XXXII., figs. 5, 6). 
Farmeria metzgerioides (figs, 9-16). — 9 Embryo from seed, x 8. 
10 Young seedling, X 5, showing cotyledons (^cot.') and first development of 
thallus {til.') ; /., the foot. 11 Larger seedling, with two leaves, X 5L 12 
Older seedling, with first secondary shoot forming (9.9.), X 5J. 13 Seedling 
with two thalli, from above, X 5^. 14 Two seedlings starting from the 
seeds in a capsule enclosed in the old bracts {hr.), X 5J. 15 Seedling with 
two thalli, X 5L 16 The same seedling as in fig. 13, from below. 
Plate XXXVII., Farmeria metzgerioides (figs. 1-9).— 1 Young plant, x 
5 ; the cotyledons and primary axis are still present, while the thallus has 
grown out and branched {hr.), the secondary shoot ( 9 . 9 .) being on the 
posterior side of the branch. 2 A thallus forming flowering shoots in 
December, x 4. 3 Thallus with branch {hr.) emerging on anterior side of 
secondary shoot : the arrow points towards the apex of the thallus. 
4 Stamens, X 5. 5 Conteuts of ovafy. from above ; the thick distal 
