. Morphology of gymnosperms. Gymnosperms; Plant morphology. CONIFERALES (PINACEAE) 245 base, and two inverted basal ovules (figs. 270, 271). Among the Taxodineae and Cupressineae there is a single bract or scale structure with two distinct apices (dorso-ventral) at the free and enlarged end and bearing one (Juniperus) to many (Cupressus) ovules. In Juniperus this structure becomes fleshy in the organization of the so-called "; Among the Araucarineae there is a prominent bract, a ligule-like ovuliferous scale, which is obvious in Araucaria, but absent or, according to Aase (233)
. Morphology of gymnosperms. Gymnosperms; Plant morphology. CONIFERALES (PINACEAE) 245 base, and two inverted basal ovules (figs. 270, 271). Among the Taxodineae and Cupressineae there is a single bract or scale structure with two distinct apices (dorso-ventral) at the free and enlarged end and bearing one (Juniperus) to many (Cupressus) ovules. In Juniperus this structure becomes fleshy in the organization of the so-called "; Among the Araucarineae there is a prominent bract, a ligule-like ovuliferous scale, which is obvious in Araucaria, but absent or, according to Aase (233), represented only by a sUght swelling in Agathis, and a single imbedded ovule some distance above the base (figs. 272, 273). A brief account of the history of the ovuliferous scale will be of interest. Before 1827, in which year Robert Brown announced gymnospermy (i), the ovule was regarded as a pistil, and the related parts were variously interpreted. Brown's conclusion as to a naked ovule was de- rived from a compari- son of the so-called "ovule" (nucellus) of cycads and conifers with the ovule of angiosperms. His corollary was that the ovuliferous scale is an open carpel, but his statement that this so-called carpel is a leaf in the axil of a bract met strong opposition. In 1839 ScHLEiDEN called attention (2) to the fact that Brown's "fohum in axilla folii" is a morphological impossibility, and that the ovuliferous scale must be a flattened axis in the form of a placenta, the axial nature of placentas in general being one of Schleiden's peculiar views. This view of the branch nature of the ovuliferous scale was concurred in later by Baillon, Dickson, Strasburger, and Masters, but without regarding the axis as a placenta. In 1842 A. Braun (3) first advanced the theory tha,t the ovuliferous scale represents the first two leaves of an axillary shoot, which are. Fig. 270.—Pinus Laricio: diagram of ovule and associated structures; h, bract; s, ovuliferous s
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