CONIFERS. 
or at a greater height. In Sabina and Calliiris quadrivalvis (Fig. 352) only two 
decussate pairs of carpels separate like a star at the time of flowering ; in Sabina 
the ovules stand in pairs in the axils of the two lower carpels, right and left of 
their median Hne, some of them being frequently abordve ; in Calliiris quadri- 
valvis a pair occurs on each of the lower carpels and a pair higher up ; but this 
position can only be explained by further investigation of the history of their 
development. In Thuja and Cupressus there are three or four decussate pairs of 
carpels, in Taxodium a still larger number ; in Thuja and Taxodium two erect 
ovules are situated at the base of each of the central pairs of carpels, springing 
from the right and left of their median line ; in Cupressus there are a considerable 
number at the base of each carpel. In Arceuthos drupacea and Frenela verrucosa 
the fruits (in the collection at Würzburg) consist of alternating whorls of three 
carpels, opening, in the last species, after the seeds become ripe, like a six-lobed 
capsule. Each carpel is swollen on its inner side into a thick placenta ascending 
from the base to the apex, and bearing numerous winged seeds which stand in 
transverse rows of threes ; there are from four to six of these rows on each carpel, 
the whole inner side therefore bearing seeds nearly up to the apex. 
So far as the relative positions of the parts of the flower can be explained 
Fig. ^s,-2.— Calliiris quadrivalvis; A female flower (magnified) ; d d two pairs of decussate leaves (carpels) in the 
axils of which are six ovules (Ä j) ; B vertical longitudinal section of an ovule through its broader diameter ; KR the 
nucellus still without an embryo-sac ; i the tubular elongated integument with the micropyle m. 
without going back to their earliest stage, a great diversity is thus shown in the 
two families of Taxineae and Cupressinese ; the ovule is terminal in Taxus^ lateral 
beneath the summit of the axis in Salisburia, carpellary leaves appearing to be 
entirely absent. In Podocarpus and Phyllocladus they are indicated indeed, as small 
scales, the ovules springing from their axils ; but they are small and do not at any 
time constitute a pericarp. A structure of this kind, in the form of a berry or of a 
chambered woody fruit, is indeed formed after feriilisation in the Cupressinese, the 
carpels either becoming fleshy and growing together (as in Juniperus and Sabina), 
or becoming woody and closing in laterally by their peltate expansions (as in 
Cupressus, Thuja, and Calliiris), or presenting the appearance of the lobes of a 
unilocular capsule {e.g. Frenela)] but the carpels are in these cases at first entirely 
open. In Juniperus communis the ovules form a whorl alternating with the carpels ; 
in the other genera they stand in pairs or in larger numbers at their base, or cover 
the whole of their inner side (as Frenela). 
In the Abietineae the well-known cones are the female flowers (or rather fruits). 
The cone is a metamorphosed shoot, its axis bearing a number of crowded woody 
scales arranged spirally, the ovules arising on them rarely singly, usually in pairs, 
occasionally in larger numbers. In the Abietineae {Abies, Picea, Larix, Cedrus, and 
