PAPERS READ. MICROSCOPICAL COLLECTIONS IN FLORIDA. By C. C. MERRIMAN, of Rochester, N. Y. It has been my fortune during the past two winters to spend a few weeks in the regions of central Florida. Lake Harris is the most southern and the most beautiful of the cluster of lakes which forms the source of that exceedingly picturesque river, the Oklawaha. With high banks and surrounded by a belt of hummock land, as rich as any that Florida affords, this lake is becoming settled upon, and the lands are fast being taken up by enterprising southerners for orange groves and pine-apple plantations. The sojourner will find the society of this lake settlement intelligent and hospitable beyond anything that would be suspected in so new and pioneer a country. The vegetation of this almost tropical region is so full of interest to the microscopist, and the causes conducing thereto so peculiar, that I have thought them deserving of especial mention and illustration. The absence, or at least the rarity of frosts, injurious to vegetation in these lake districts, gives the longest possible season for the growth and maturity of such organs as are best or especially adapted to the exigencies of Florida plants. There is a period of rest, usually comprising about the three winter months, after which vegetation takes up and continues its growth again as if there had been no period of interruption; so that practically there is a continuous development of plant life, whether annual or perennial, from birth to death. The soil of Florida, as of all the south Atlantic seaboard, is sandy and naturally barren. No polar glaciers have ground up for these regions, as for the northern states, a rich and abundant alluvium, sufficient in itself for the production of a rapid and vigorous vegetation. The south has apparently only the siftings of our northern soil, carried down to the ocean by rivers, and then washed up by the sea-waves to form their interminable sandy plains. But to compensate for this natural infertility of soil the atmosphere, especially of southern Florida, abounds in all the elements of plant growth. The winds which come up from the Gulf on the one side, or the Atlantic on the other, are charged with moisture, and bear also minute quantities of nitric acid and saline compounds; while the exhalations from the swamps and marshes furnish in abundance the salts of ammonia and carbonic acid. Now to utilize these precious products from the air it is necessary for plants to have peculiar organs, such as absorbing glands, glandular hairs, stellate hairs, protecting scales, and a variety of other special appendages. All these have been developed by time and necessity in remarkable profusion and perfection on the vegetation of southern Florida. Although the meagre soil produces no nutritious grasses, and scarcely enough of an honest vegetation to keep an herbivorous animal from starving, yet there is an abundant flora, such as it is-air plants, parasitic growths, insectivorous plants, and strange herbs seeking a livelihood in any other way than the good old honest one of growing from their roots. It is this fact which makes the microscopical interest of botanical researches in central Florida. One can scarcely examine, with a two-thirds objective, the flowers, leaves or stems of any plant growing there, without discovering some beautiful or striking modification of plant hairs, or scales, or glands, or other absorbing or secreting organs. We will notice first the Onosmodium as found in Florida — O. Virginianum. It grows from Virginia south, but is more glandular, I think, in Florida than anywhere else. It will be almost the first plant one will stop to observe on entering the piny woodsa dark green, narrow-leaved, biennial herb; its straight stem of the second year's growth,, about a foot high, bearing a raceme-like cluster of flowers, coiled at the end, and straightening out as the flowers expand. The leaves of this plant are thickly studded on both sides with stiff transparent hairs, lying nearly flat on the surface, and all pointing towards the tip end of the leaf. At the base of each hair is a cluster of glandular cells, amounting sometimes to fifty or more, and arranged in beautiful geometrical forms. When pressed and dried in the herbarium, the body of the leaf turns to a very dark green, almost black, and on this background, with a half-inch objective, the hairs stand out like sculptured glass, and the glands like mosaics of purest pearls. I think it is the most attractive opaque object that can be shown under the microscope. That these glandular cells, covering, as they do, nearly half the surface of the leaves, especially the upper surface, and differing from all other vegetable cells, subserve an important purpose in the sustenance of the plant, there cannot be any doubt. But just what that purpose is, or what is the mode of operation, I think," has never been ascertained. In the same locality will very likely be found the most beautiful of all the Croton plants, the C. argyranthemum. Unlike the other Crotons, which are bushes, this is an herb growing only about a foot high, with a milky sap which exudes when the stem is broken. The leaves are silvery, verging in some cases to a bronze color, and are thickly covered on the upper side with most remarkable and beautiful stellate scales. The flower buds and stems when pressed make much more beautiful opaque objects than the leaves. The object of these scales is without doubt to prevent the too rapid evaporation of the moisture stored up in the plant. They are the exquisitely woven blankets which preserve the precious juices so laboriously gathered. The same kind of covering is spread over the leaves and stems of all the air-plants of Florida, and doubtless for the same purpose. The well-known Florida moss, although not a moss, but a member of the Pineapple family (Tillandsia usneoides), is an exceedingly beautiful object under the microscope. Each hanging stem is overlaid with filmy white scales, every one of which is fastened in its place by what would seem to be the stamp of some miniature seal on golden-tinted This plant, as ordinarily seen on the live-oaks near cities, is a dirty-looking and unattractive object, and goes by the name of "black moss." But in out-of-the-way places, removed from the dust and smoke of settled localities, it is pearly white and exceedingly beautiful, both to the naked eye and under any power of magnification. Florida moss should be preserved with only very slight pressure, just enough to make the threads lie straight. After it is dried in this way, small cuttings may be mounted in the ordinary cells for opaque mounting. wax. On the high banks of the lake, and in the adjoining fields, may be found the large leaved and vigorous growing Calicarpa (C. Americana), sometimes called the French mulberry, a bush growing some five or six feet in height. The under side of the leaves of this plant is nearly covered with little round yellow sessile glands, flattened on top and marked off into eight or ten sections |