[Illustration: PLATE I.] FOOTNOTES: [D] Todd Prof. J. E.: On the Flowers of _Solanum rostratum_ and _Cassia chamæcrista_, Amer. Nat., vol. XVI, pp. 281-287, 1882. A brief review of Todd’s paper is given by Dr. P. Knuth, Handbuch der Blutenbiologie, Leipzig, 1898. [E] According to Carruth—Carruth, J. H., Catalogue of Plants seen in Kansas, with additions by Prof. F. H. Snow and Prof. E. Hall—_S. rostratum_ first appeared in Kansas in 1864. This date probably refers to eastern Kansas. Dr. S. W. Williston informs the writers that it appeared around Manhattan in 1860 or 1861. [F] One specimen observed growing in rich soil back of a feed-store in St. Joseph, Mo., in early September had a diameter of over seven feet and a height of three feet. The plant might be considered as normally developed, having produced apparently the normal number of seed pods, and so would not be classed with the rank vegetative development which plants sometimes show when grown in very rich soil. [G] _S. rostratum_ appears to be better adapted to xerophytic conditions by its extensive root system than by any adaptation for the prevention of evaporation of water. When cut down on a warm day, the plants wilt in a very few minutes. Roots extend down sometimes for more than three feet, so that the plants generally appear perfectly fresh when others around are wilted and drying up. [H] Mueller, Fritz: Two Kinds of Stamens with Different Functions in the same Flower, Nature, vol. XXVII, pp. 364, 365, 1883. [I] Experiments for the determination of the fertility of close and cross-fertilization are always interesting, but are of especial interest in the case of a plant such as _S. rostratum_, in which, if the method of pollination described by Professor Todd is the one actually depended upon, cross-pollination is sometimes possible and sometimes impossible on the same raceme. Of course, if, as suggested in the latter portion of this paper, the method of pollination suggested by Professor Todd is not the only one, these experiments do not have the interest which they otherwise would. [J] As will be remarked, the above insects were all taken August 5 and 6. Careful collecting extending over a considerable period of time would doubtless secure many other forms which visit the plant more or less frequently. [K] Meehan, Thomas: On the Fertilization of _Cassia marilandica_, Proc. Acad. Nat. Sci. Phila., 1886, pp. 314-318. [L] Meehan, Thomas, _loc. cit._