other. This I have noticed in Berteroa incana and Tklaspi arvensis, in whose ovules the lower part of the cylindrical nucleus is thicker than the upper, and the two integuments arise seemingly both at once from the lower thickened part, at one time all round and at the same height, at another time unilaterally. As in these cases, true ovule-coats are developed on one side first, and not equally all round, it does not seem unfair to infer the possibility of their appearance in two distinct places or by two gibbi. The alternation of the two lips of the ovule-coat of Taxus, with the two uppermost bracts, may be understood to depend on the existence of more ample room for development on the two sides where there are no bracts, than on the other two, where the bracts come in contact with the ovule. It is well known, that organs increase most in size and vigour in those parts which are free and not interfered with by other organs, while they are weaker and smaller, where they are pressed on by neighbouring organs and deprived of nutriment. In the Abietineæ this may be the cause of the bilobation of the ovule-coat, as the two teeth in Abies excelsa, for instance, are on those sides of the ovule which are not pressed on either by the axis or the scale.
The second part of Baillon's proposition, regarding the flowers of Conifers, is that they always arise from the axis and never from a leaf or bract, or rather carpel. This is shown to be erroneous as to Abietineæ, at least by the monstrous larch described above. It is also excellently refuted by Baillon and Payer's own observations on Pinus resinosa. As described by Baillon, the scales of Pinus resinosa are developed in the following manner. The scale appears first as a small, dorsally compressed, broad boss in the axil of the bract. From the first boss spring three others, one central and two lateral The lateral bosses become broader, assume the form of auricles, cohere externally, and, increasing mainly in width, are gradually converted into an obliquely ascending lamina, the scale itself, which bears a little above the middle in the median line, the subcentral boss, "the organic apex of the axis," which axis produces no more appendages, increases very little in size, and in the adult state, presents the form of a hook bent inwards and downwards. On the upper surface of the lateral wings, towards their lower margin, which is turned towards the primary axis, the ovules are, according to Baillon, produced at a later period.
From this description it is evident that three distinct organs, all differing in period oi origin, can be distinguished, each of which is developed from that immediately preceding it.
1. The axis which originates in the axil of the bract.
2. The ear-shaped organs, which spring laterally from this axis, and are called by Baillon the two lateral lobes. These ascend obliquely and form the greater part of the scale, but are so situated with respect to the minute axis, as manifestly to exhibit the character of appendicular organs. They form two nearly right angles with the ascending axis, and spread out laterally and almost horizontally,
