. Edinburgh New Philosophical Journal. 188 Dr Dickson on some of the Stages of Development longation of the extremity of the ovule, although very curious, cannot I think be of much importance, either morphologically or physiologically, since it is comparatively late in its appari- tion, and, although of very frequent, is not of universal occur- rence. Regarding the subsequent stages in the development of the pistil, I need not say much. The ovule always remains ex- posed by the anterior and posterior notches between the apices of the carpels, but always to a relatively less extent as de- velop
. Edinburgh New Philosophical Journal. 188 Dr Dickson on some of the Stages of Development longation of the extremity of the ovule, although very curious, cannot I think be of much importance, either morphologically or physiologically, since it is comparatively late in its appari- tion, and, although of very frequent, is not of universal occur- rence. Regarding the subsequent stages in the development of the pistil, I need not say much. The ovule always remains ex- posed by the anterior and posterior notches between the apices of the carpels, but always to a relatively less extent as de- velopment advances. The apices of the carpels never pro- ject as style-like prolongations, but are closely applied to the sides of the ovule. (See figs. 12 and 13.) In the flower represented in fig. 10, the unsymmetrical development of the wing-like margins of the pistil has com- menced. The great wing is developed sometimes on the right, some- times on the left side of the pistil; but the side upon which it occurs is constant in any given cone. This, I find, is de- pendent upon, or at least correlated with, the direction of the generating spiral of the cone. If the cone-spiral be from right to left (supposing the observer to be in the axis of the spiral), the wing is developed on the right side of the pistil ; but if on the contrary, the cone-spiral be from left to right, the wing is developed on the left side of the pistil* The relation of the unequal development to the disposition of the scales may be briefly described as follows:—If we take a bract- scale—say No. 1 of the cone- spiral—we find that of the two bract-scales immediately applied ft\ ) v^^^ y to its upper or inner surface, No. 6 extends from one side to i past its middle line, and entirely \ covers the flower of bract No. 1; while bract No. 4 extends from the opposite side just to the margin of No. 6, without overlap- ping it. It would appear almost as if the development of the * I have examined six conee with r
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