3 20 
CONIFERAE 
their importance decreases and at about 40° N. the C. become prac- 
tically confined to the mountains. Here we find in Japan and China 
a region of development characterised by Cephalotaxus, Pseudolarix, 
Cryptomeria, Cunninghamia, Sciadopitys, Chamaecyparis, Ginkgo, 
&c., mostly endemic genera. In Pacific N. Am. is another region, with 
Pseudotsuga Douglas ii, Sequoia, Cupressus Lawsoniazia , Thuja gigan- 
tea , and Libocedrus decuri'ens , together with endemic sp. of Abies, 
Tsuga, Pinus, &c. The Himalaya forms another great centre, with 
many peculiar sp., e.g. Cedrus Deodara , Pinus excelsa and other sp., 
Picea sp. Tsuga sp. &c. The C. of the N. hemisphere are separated 
from those of the S. by a broad band of tropical forests, &c., only 
partially broken by groups of C. on the Mts. of the Indo-mal. region 
and America. In Australia we find Araucaria, Agathis, Podocarpus, 
&c. In Tasmania, New Zealand and Chili appear Phyllocladus, 
Fitzroya, &c. S. America has Araucaria sp. Podocarpus sp., and 
others. Few genera and no sp. of C. appear in both N. and S. 
hemispheres ; each sp. is limited to a well-defined area. 
The C. are trees or shrubs, usually of monopodial growth, often 
reaching considerable or even (Sequoia) gigantic size. Typically, as 
may be seen at a glance in a fir or larch plantation, a certain amount 
of growth is made each year and a number of branches are also 
formed much at the same level, so that in trees of moderate size the 
number of * whorls ’ of branches is an index of the age. Later on the 
lower branches usually die off and the branching near the apex 
becomes less regular. The main stem is radially symmetrical, but 
the branches, which often grow almost horizontally, have a tendency 
to dorsiventrality ; this is expressed in a two-ranked arrangement of 
the leaves, twisting of the leaves on their stalks, and so on. Many 
C. show a difference in their shoots; some {long shoots , ox shoots of 
unlimited growth) grow continuously onwards, except for the periodi- 
cal interruption in winter ; others {short shoots , shoots of limited 
growth, or spurs) grow only to a definite size, usually very small, and 
bear a few leaves. Intermediate conditions occur in Ginkgo, Larix, 
Cedrus, Taxodium, &c. When both kinds occur the foliage leaves 
are often borne on the short shoots only (see Pinus &c. for details). 
The green leaves are usually entire and are either linear or take the 
form of closely appressed scales (Cupressus, &c.). The only exception 
is the curious genus Ginkgo, the sole surviving relic of an extinct 
type which in many respects approximated to the Cycads. Mention 
may also be made of the curious ‘double-needles’ of Sciadopitys and 
the flat green short shoots of Phyllocladus {q.v.). 
Anatomically, the C. resemble Dicotyledons in all important 
points. A very general feature of the class (exc. Taxus) is the pre- 
sence of resin passages in all parts of the plant. The leaves exhibit 
a somewhat peculiar internal structure (see text-books), which how- 
ever is admirably suited to xerophytic plants, under which class most 
