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572 inches long. Scales dark brown on the inner surface, oblong, ending in a rhomboidal apophysis, which is variable in form in different varieties and even in the same cone ; flattened, with a transverse keel and an elevated or depressed umbo, or raised and pyramidal, with four to five concave sides ; occasionally the apophysis ends in a hooked process. The cones open in spring to let out the seeds, which may be carried by strong winds to an immense distance ; and the empty cones usually remain on the tree till the following autumn. Seeds long-oval, $1/8$ to $1/5$ inch, some blackish, others grey in colour, surmounted by a wing half-oval in shape, which is three times as long as the body of the seed.

Seedling.—Cotyledons, four to seven, triangular in section, linear, slightly curved upwards, about $4/5$ inch long; stomata absent on the outer surface, present on the inner two surfaces, without wax, so that the cotyledons are green in colour and not glaucous. Primary leaves elliptic in section with hairs on their edges. The seedling grows about 2 to 4 inches high in the first year, ordinary needles being produced in the second year; branches usually appear in the third year. The primary root is long, attaining about 8 inches in the first year, and giving off many lateral fibres.

The common pine, spread over an immense geographical area and growing in the most diverse conditions of soil and climate, exhibits considerable variations in most of its characters. The stem may be straight and cylindrical with a single leader, only branching at the top and giving rise to a flattened crown of foliage in old age; or it may be dwarf, branched from the base and crooked, simulating the smaller forms of Pinus montana. The young cones are usually reversed immediately after flowering ; but in certain regions they remain erect. The adult cones vary in size and shape and in the form of the apophyses, which may be flat or raised, pyramidal or hooked ; but all these variations in the apophysis may occur on the same cone. The male flowers may be yellow or reddish in colour. The leaves vary in length from one to four inches, and may be broad or narrow, stiff and sharp-pointed or soft in texture; and in some cases they are much more glaucous than in others. They vary in duration from two to five years,

Many of these varieties occur in individual trees in the same forest; and in many cases, when the condition of the soil is changed as by draining, pines which have been small and stunted assume the ordinary tall form, and the shape of the cones probably does not remain constant, when the seedlings are raised in a new locality. It is difficult on this account to establish clearly marked geographical varieties.

The experiments, which have been carried out at Les Barres, over a long term of years, show, however, that there are races of pines, which preserve their characters of straightness of stem, quickness of growth, or the reverse; but these races cannot be distinguished by characters of cones or leaves; and are the result of the selection of seed from vigorous or weak individuals.

1 Cf. Pardé, Arboret. Nat. des Barres, 71 (1906), where a full account is given of the plots of Riga, Haguenau, Scotch, and certain French varieties of Pinus sylvestris, which were mostly planted between 1823 and 1835.