CONIFERS. 



265 



the ; ' cone-scale" in the other order of Pinoidese. On the side 

 of the ovuliferous scale, turned towards the axis, are situated two 

 ovules with micropyles directed inwards. The seeds are most 

 frequently provided with a false wing (a tissue-like part of the 

 surface of the ovuliferous scale). Cotyledons, more tluut '2, 

 verticillate. Fertilisation, does not take place until some time after 

 pollination. In Pinus, for instance, the pollen-tube only penetrates 

 the nucellus for a short distance during the year of pollination, and 

 then ceases its further growth, fertilisation not taking place until 

 after the middle of the next year; whilst the seeds ripen about a 



If 



FIG. 263. .4 Abies : c the cover-scale ; s ovuliferous scale, or " cone-scale " ; sic ovules in 

 a .young condition. 1> Pinus : ovuliferous scale with two ovules (s) ; m the tvro-lobed 

 micropyle; c " mucro " ; b the cover-scale behind. C Abies : ripe "cone-scale" with two 

 seeds (su); /winy of seed. 



year and a half after pollination. In the Larch and others, the 

 seeds are mature in the autumn succeeding pollination. 



Abies (Fir). The leaves are often (e.g. Ab. pectinata) displaced 

 into 2 rows, flat and indented at the apex, with 2 white (wax- 

 covered) lines on the under surface, in which the stomata are situ- 

 ated. The leaf-scars are nearly circular and do not project. The 

 cones are erect. The cover-scales and the ovuliferous scales separate 

 from the axis, to which they remain attached in other genera. 

 Tmiga has leaves like Abies, but by the slightly projecting leaf-scars, and cones 

 with persistent scales, it forms the transition to Picea. Pseudotsuga has leaves 

 similar to those of Abies and persistent carpels as in Picea, but the cover-scales 

 grow as in Abies and project beyond the ovuliferous scales (P. dotiglasii, Fig. 

 267). These two genera are considered as sub-genera of Abies. Picea. The 

 leaves project on all sides, square and pointed ; the leaf-scars are 



