The structure of the female flower, or inflorescence, of Gymnosperms, has been the cause of more discussion than most questions of morphological botany. In earlier times, the views of botanists on this difficult subject were necessarily uncertain and arbitrary, because no accurate observations had then been made either of the perfect flower or of its evolution. As the study of morphology depends upon the correct knowledge of the taxis of the leaves and branches, the structure of the flowers of Gymnosperms could not possibly be understood at an earlier period. It is not my intention here to enter into details (which may be readily found elsewhere) reading the various explanations which have been proposed; but I think it desirable to state the plain truth as respects the group of Abietineæ, so as to correct previous errors, and to obtain a basis of comparison to which the flowers of other Gymnosperms may be referred.
The true structure of the flowers of Abietineæ was described by A. Braun, as early as 1853, in the following terms, in a note of great importance, though short and modest,[2] which has been entirely neglected by subsequent writers. "The seed-bearing fruit-scales of the cones of Abietineæ, which lie in the axils of the bract-scales, have all the appearance of one-leaved shoots, but the progressive modifications of form exhibited by these scales in abnormally developed cones of Pinus Larix, prove that each scale consists of two leaves united together." In 1860[3] he expresses himself in a similar manner, only in more general terms, as to the structure of other Conifers and Cycads. The woody scales of the strobili of Abietineæ consist, according to A. Braun, of two carpels, which originate together, and are the first leaves of an undeveloped bud in the axil of the floral leaf
Before these views of Braun were known to me I was led to the same conclusions, at Bonn, in the autumn of 1858, by the examination of larch cones, which had grown out into leafy branches in the axils of the scale. My observations on these were to the following effect:—
Along the axis of these cones or strobili are inserted linear, elongated bracts, with the woody scales in their axils. The axis does not end with the uppermost scales, but is abnormally prolonged for several inches beyond the apex of the cone. Such strobili have been figured by Richard.[4] The slender prolongation of the axis differs in
- ↑ Communicated by Dr. T. Thomson, F.R.S. An abstract of Dr. Baillon's views, referred to in this paper, is given in the Nat. Hist. Review, Vol. I. Bibliography, p.92.
- ↑ Individuum der Pflanze, p. 65.
- ↑ Ueber polyembryonie und Keimung von Cœlebogyne, p. 243.
- ↑ Mémoires sur les Coniferes et les Cycadées, 1826, t 13, f. 9, fig. repetita in
