350 FLORA OF TASMANIA. [Conifer ce. 
give a connected sketch of the prominent characters of the Tasmanian genera. All are shrubs or trees, 
with the stems and branches formed on the same plan as in other Dicotyledonous plants, but differing 
from the majority of these in the rarity of medullary rays, in the highly organized structure of the tubes 
of the wood, which are studded internally with beautifully formed discoid glands j and they also germinate 
as other Dicotyledons, being exorhizal, but sometimes have three or more cotyledons to the embryo, or, as 
some consider, normally two cotyledons, but each divided congenitally to the base into two or more equal 
lobes. Their foliage presents many curious forms, and seldom resembles that of other trees, most so how- 
ever in Podocarpus, and least so in PhyUocladus and Frenela. 
Both male and female flowers are deprived of a perianth ; the males consist of single stamens collected 
in small cones ; and, from the uniformity of the tissue of all its parts, it would seem that each stamen con- 
sists wholly of an anther, whose often very beautifully constructed and highly developed connective is narrowed 
below into a short stipes (not a proper filament), and dilated above into a broad peltate scale, bearing cells 
on its margin : the pollen I have already alluded to ; the grains of the curved form in some European 
species present a unique development, the pollen-tube emitted on fecundation originating in a free cell- 
formation within the middle of the curved part of each pollen-cell. 
The female flowers essentially consist of an ovule, with no investing ovary, seated upon a scale, called 
the ovuliferous scale, which is an open rudimentary ovary ; these scales are solitary in Podocarpus, spiked 
in Dacrydimn and Pkerospkara, capitate in PhyUocladus, two and opposite in Diselma, whorled in Frenela, 
imbricate and forming a cone in Mierocachrys and Atkrotaxis. In some genera these scales bearing the 
ovules are subtended by a more or less free or adnate bract (obviously in the northern Pines) ; this bract 
is seen distinctly in some Frenelas and in Atkrotaxis selaginoides to be adnate to the back of the ovuli- 
ferous scales, and to form a beak to them; whereas in A. laxifolia and A. selaginoides it appears larger and 
broader than the ovuliferous scale, which is, as it were, adnate to its inner face. The ovuliferous scales are 
persistent in all the Tasmanian genera but Pkerospkara, in which the ripe seed and scale together fall 
away from the rachis of the spike; in Podocarpus the seed, scale, and spike fall away together; in all the 
other genera the seeds fall away from the ovuliferous scale. 
The ovules are always orthotropous ; they are solitary on each ovuliferous scale in Podocarpus, Phyl- 
hchdm, Dacrydlum, Pkerospkara, and Mierocachrys ; there are two on each scale in Diselma ; several in 
Frenela and Atkrotaxis: they are erect, pointing upwards, in Pkerospkara, Diselma, and Frenela; inverted, 
pointing downwards, in all the rest; but in Mierocachrys, Dacrydium, and PhyUocladus they become par- 
tially or wholly erect as they ripen : they are free, or inserted by a small base, in all the genera but Podo- 
carpus, in which the outer coat of the ovule (and seed) is adnate throughout its length to the ovuliferous 
scale. The ovule consists of one or rarely two rather coriaceous coats, and an enclosed nucleus, but in 
Dacrydium and PhyUocladus, which have two, the onter coat covers the ovule in a very young state only, 
forming a short sheath or incomplete annulus round the base of the ovule, at the period of impregnation 
and afterwards; a third coat appears investing the immature nucleus in some species (as in Mierocachrys) , 
whose exact nature I have not determined, but it probably belongs to the nucleus. In some genera 
[Mkroiaxis and Diselma) the outer coat is contracted at its apex into a tube; in others it forms an ex- 
briated mouth, which, after impregnation, becomes introverted. 
No account of the structure of the nucleus of the ovule of the Tasmanian species has hitherto been 
published, but it no doubt shares the peculiarities of the better-known plants of this Order, and is assumed 
to consist of a fleshy, conical body, containing an embryo-sac. After the pollen has fallen on the mouth 
of the ovule, it sends a tube, by a very slow process of growth, into the substance of the nucleus; the 
embryo-sac thereupon becomes filled with cellular albumen; after this, several cells (called I 
