SUPPLEMENTARY OBSERVATIONS, &c.[1
ORCHIDEÆ.
In the observations appended to my Paper on these two Natural Families, printed in the 16th Volume of the 'Linnean Society's Transactions,' and which relate entirely to Orchideæ, it is stated, that in several species of Ophrydeæ the Tubes, produced either directly from the grains of Pollen, or in consequence of their application to the Stigma, were found spread over the surface of the Placentæ, and not unfrequently inserted into the aperture of the Ovula. The correctness of this statement I have confirmed, during the present season, by numerous observations, not only on the same, but also on several other species. Another remarkable appearance observed in some of these species, especially in Orchis ustulata, fusca, Morio, and in Ophrys apifera, and which indeed I had before met with, but neglected to mention in my Paper, consists in the elongation and protrusion of the jointed or cellular filament connecting the upper extremity of the Embryo with that of the original nucleus (the Tercine of M. Mirbel).
The Filament so protruded often equals the whole Ovulum in length, and its elongation seems to depend not only on the enlargement of each of the cells or joints, of which the included thread consists, but also on the production of additional joints.
As, however, the Pollen tube is found applied to the aperture of the Ovulum uniforndy before either the Embryo or its thread is distinguishable, and as I have
