I. — THE SCOTS FIR. 
Pinus sylveslris Linne. 
F LOWERING Plants, which are known technically as Spermatophyta or 
Phanerogamia, are divided into two main divisions, the Gymnospermia (Greek 
- yvpvb< ?, gumnos , naked ; crnepixa, sperma, a seed) and the Angiospermia (Greek 
ayyeiov, angeion , a box), according to whether their seeds are, or are not, enclosed 
in a closed receptacle, the ovary. Of these, the Gymnosperms are, geologically, 
the more ancient, but are now by far the smaller group, including four Classes, 
about 48 genera, and 450 species. 
The two Orders of the Conifer ce (the only Class represented in Britain), 
Araucariace<e and Taxace<e, are distinguished, the former by bearing perfect cones, 
between the scales of which the seeds are concealed, the latter by less-developed or 
absent carpels, not forming perfect cones, and with more prominent or exposed seeds 
surrounded by a fleshy cup. The former includes the Kauri, Monkey-puzzles, 
Pines, Cedars, Larches, Spruces, Firs, Cypresses, and Junipers ; the latter, the Yews 
and the Maidenhair-tree. Both are, therefore, represented, though only by one or 
two species, among British plants. 
The Araucariaceas include two Families, the Abietine <e and the Cupressine# , of 
which the former is characterised by bearing its leaves singly and in a spiral on the 
shoot, and by having the ovules on the scales of the cone so reversed that the 
micropyle, or opening by which the pollen enters, faces the axis of the cone. 
The genus Pinus is by far the largest among Gymnosperms, comprising some 
seventy species, i.e. one-fifth of the whole. They are all evergreen trees, abounding 
in resin and bearing needle-like leaves and woody cones ; and occur, generally 
“ socially,” or in “ pure ” forests, in the North Temperate Zone, or on mountains in 
the northern part of the Tropics. They produce two kinds of shoots, “long ” and 
“short”; the long ones bearing only scale-leaves, but increasing indefinitely in 
length ; whilst the short shoots are of limited growth and bear a sheath of scale- 
leaves and the needles, of which there are two, three, or five on each shoot, according 
to the species. The scales of the cones become woody and thickened at their upper 
extremities into the rhomboidal apophyses which form the tesselU or spirally-arranged 
mosaic-like masses that constitute the exposed surface of the unripe cone ; and, 
though when ripe they diverge so as to allow the seeds to fall out, they do not fall 
off" separately, like those of Cedars and Silver Firs, but the cone falls whole. 
Most Pines inhabit poor, dry, porous soils, into which they send down deep 
branching tap-roots ; and the needle-leaves show adaptations to a scanty supply of 
water in their very thick epidermal and hypodermal cells and in the stomata (or 
transpiration-pores) being few in number and sunk at the bottom of deep pits. It is 
this xerophytic habit that renders our Scots Fir or Northern Pine so much better 
suited to the poor Bagshot and Lower Greensand wastes of Surrey and Bedfordshire 
than are our broad-leaved trees. 
