536 



BOTANY 



PART II 



in the first place. The male flowers (cf. Fig. 424, p. 481) consist of an axis bearing 

 scale-leaves at the base, and, above this, numerous stamens; the pollen -sacs 



(mici'osporangia) are situated on the lower surface 

 of the stamen. In the Abietineae in the narrower 

 sense there are two pollen-sacs, but in Agathis 

 and ArmLcaria there are 5-15. The projecting 

 tip of the sporophyll varies in size and appear- 

 ance, but is as a rule triangular. The micro- 

 spores are usually winged. The female flowers 

 are always cones, consisting of an axis bearing 

 the closely approximated scales, which protect 

 the ovules ; the scales later become lignified. lu 

 Agathis and Araucaria each scale bears a single 

 anatropous ovule at its base. (The cone-bearing 

 Cupressmeae have an outgrowth of the scale on 

 which the ovules are seated ; tlie outgrowth is 



Fig. 50". — Pinus silvestris. Ovuliferous 

 scale (//•) bearing two ovules s and 

 tlie keel c. The bract-scale 6 is 

 visible behind. The free margin of 

 the integument of the ovule forms 

 two prolongations (?rt). (x 7.) 



not sharply marked off from the scale.) 

 The condition of aff'airs in Sequoia 

 and Sciado2nfys is similar, but the 

 outgrowth is more definitely defined ; 

 each scale bears 4-9 anatropous ovules. 

 In the Abietineae proper the limits of 

 the two scales are still more marked. 

 The two anatropous ovules are borne 

 on an inner scale, which, at its base, 

 is continuous with the scale of the 

 cone. The outer scale is called 



THE BRACT SCALE, THE INNER, THE 

 OVULIFEROUS SCALE (FigS. 507, 508). 



The ovuliferous scale is the more 

 strongly developed and it is the part 

 that becomes lignified and aff"ords pro- 

 tection to the ovules. Even at the 

 period of flowering the bract scale is 

 usually concealed by the ovuliferous 

 scale and only to be detected on close 

 inspection. In other forms, however 

 {e.g. Abies hracteata, A. pedincda, 

 Fig. 508, B, Pseudotsuga Douglasii, 



Fig. SOS. — Abies peel innta. ,1, Male flower ; /, scale- 

 leaves ; /i, sporoi)hylls. 7;, Cone. C, Carpel, viewed 

 from below (dorsal surface), showing the fertile 

 and cox'er-scalf ; D, the same viewed from abo\'e 

 (ventral surface). (After Berg and Schjiidt ; 

 A, C, D, nat. size ; B, reduced.) 



etc.), the bract scales even in the 

 older cone project jtromincntly between 

 the ovuliferous .scales. 



The view here followed, tliat tlie ovuliferous scale is a placental outgrowth of 

 the bract-scale bearing the macrosporangia, and that its increase in size can be 



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