ANSWERS TO CORRESPONDENTS. M. B.. Milwaukee, Wis.-The earth sent in the box was so dry when received that the larvae said to be there coull not be found. They were probably larvæ of a small fly. Tie a pie re of gauze rou ad the flower pot and upon the stem of the plant, and cat som 6, the lase its when they develop. AMATEUR. Pembina.- Not unless you send better specimens, neatly put up. Nos.1 and 2 we happen to recognize. 1, Penced imum fœniculaceum Nutt. 2, Cymopterus glom. eratus DC. But they should be collected after the fruit is formed. Same of 3, which is Carex filifolia Nutt. BOOKS RECEIVED. The Bird Fancier's Companion. 16mo. 1871. New York and Boston. Fifth Report of the Commissioner of Fisheries of the State of Maine, for the year ending 1871. Svo pamph. 1872. Augusta. The Development of Limulus Polyphemus. By A. S. Packard, Jr. 4to. 56 pages. 3 plates, 1872. Contributions to the Fauna of the New York Croton Water. Microscopical observations during the years 1870-1. By Charles F. Gissler. 8vo. pp. 23, woodcuts and 5 plates. New York. 1872. Vegetable Parasites and the Diseases caused by their growth upon man. By James C. White. 8vo. pp. 50. Boston, 1872. Journal of the Quekett Microscopical Club, No. 18. Apr., 1872. London. Nova Acia Regia Societatis Scientarum Upsaliensis. 4to. Ser. 3. Vol. vii. Fasc. i.-il 1869-70. Upsalia. Astronomical and Meteorological Observations made at the United States Naval Observatory during the year 1869. 4to. 1872. Washington. Philosophical Transactions of the Royal Society of London. 4to. Vol. 160. Parts 1-II, 1870. Vol. 161. Part 1. 1871. London. The Royal Society List, 30th Nov., 1870. 4to pamph. Second Annual Report of the Commissioners of Fisheries of the State of New Jersey. 8vo pamph. 1872. Trenton. On Organic Physics. By Henry Hartshorne. 8vo. Read before the American Philosophical Society, Jan. 19th, 1872. Discovery of Additional Remains of Pterosauria, with descriptions of new species. Discovery of the Dermal Scutes of Mosasauroid Reptiles. (From the Amer. Jour. of Science and Arts. Vol. iii., April, 1872.) By O. C. Marsh. 8vo pamph. New Haven. Report of the Geological Survey of the State of New Hampshire. By C. H. Hitchcock. 1871. 8vo pamph. Nashua. On the Mode of the Natural Distribution of Plants over the Surface of the Earth. (Boston Soc. Nat. Hist.; First Walker Prize Essay.) By Albert N. Prentiss. 8vo pamph. 1872. Ithaca. Notice of a New Species of Hadrosaurus. By O. C. Marsh. Received March 21st, 1872. The General Principles of Organization and the Evolution of Organic Forms. First annual address before the Alumni Society of the medical department of the University of Nashville. Delivered Feb. 23, 1870. By Jerome Cochran. Svo pamph. 1871. Nashville. Remarks on a paper entitled "On Some Phases of Modern Philosophy," by Eli K. Price. By Edward D. Cope. Svo pamph. 1872. On the Mineral Resources of North Carolina. By Frederick A. Genth. 8vo pamph. Philadelphia. 1871. Eleventh Annual Report of the Educational Department of Kansas. 8vo. 1871. Topeka. Preliminary Description of Hesperornis regalis, with notices of four other new species of cretaceous birds. By Prof. O. C. Marsh. (From the Am. Jour. of Science and Arts, May, 1872.) Geologischen Reichsanstalt. Band xxi. No. 3. Juli, August, September. 4to. 1871. Wien. The American Journal of the Medical Sciences. 8vo. No. 126. April, 1872. Philadelphia. Verhandlungen der k. k. geologischen Reichsanstalt. 8vo. No. 11. 1871. Notice of the Address of T. Sterry Hunt before the American Association at Indianapolis. By James D. Dana. (From the Am. Jour. of Science and Arts.) Feb., 1872. Annual Report of the Minnesota Historical Society to the Legislature of Minnesota for the year 1871. 8vo. 1872. St. Paul. Conchological Memoranda. No. ix. By R. E. C. Stearns. (From Proc. Cal. Acad. Nat. Sci. Sept. 4, 1871.) Acad. Nat. Sci. Philadelphia.) 1872. Record of a few Molds in the Collections of E. C. Howe found in N. Y. 1872. The Canadian Entomologist. Vol. iv. No. 2. The Entomologist's Monthly Magazine. 92. Jan., 1872. London. No. The Field. Nos. from Jan. to May, 1872. The Lens. Vol. i. No. 2. 1872. Chicago. 18 and 19. 1872. La Revue Scientifique. Serie 2. Nos. 34-45. Bulletin of the Torrey Botanical Club, Vol. The Scottish Naturalist. Vol. i. No. vi. 1872. The Geological Magazine. Vol. ix. No. 4. ABOUT thirty years ago, two Fedias with fruits of singular shape were discovered by Mr. Sullivant, near Columbus, Ohio, and published by him as new species under the names of F. umbilicata and F. patellaria. They soon disappeared from their original station, and no botanist seems to have met with either of them again until the Rev. S. W. Knipe of the Delaware Water Gap collected, in the spring of 1870, a few specimens of F. patellaria, in Westmoreland County, Pa., and early in June, 1871, a large supply in the neighborhood of Columbia on the Susquehanna River, where it grew in great profusion along with the F. radiata of Michaux. Specimens of this plant, placed in my hands by the collector, exhibited such diversities in the fruit as to suggest the idea that both it and F. umbilicata might in the end prove to be forms of F. radiata. Dr. Gray, to whom the conjecture was communicated, kindly furnished fruits from Mr. Sullivant's plants, to complete. the chain of evidence, and the information that F. umbilicata had also been rediscovered, last summer, on the Hudson River. The Manual of Dr. Gray contains five species of Fedia; one an introduction from Europe (F. olitoria Vahl.), and four indigenous. All of them are much alike in general appearance, and amongst the latter especially the resemblance is so great that their specific characters are derived from the fruit alone; but how far these char Entered according to the Act of Congress, in the year 1872, by the PEABODY ACADEMY OF SCIENCE, in the Office of the Librarian of Congress, at Washington. AMER. NATURALIST, VOL. VI. 25 (385) acters are constant and reliable, it will now be my endeavor to show, aided by illustrations from the p ncil of Mr. Knipe. Fedia olitoria Vahl., Fig. 102. Fruit; a, side view; b, cross section with the confluent empty cells shaded. The spongy mass (c) on the back of the fertile cell clearly separates this naturalized foreigner from our native species. It differs also in its more humble and diffuse habit, and the Fig. 102. 10 Fedia olitoria. pale blue color of its corolla. ry, as seen in the five well-de fined dorsal sutures (103 b, s), is quinary. A Fig. 104. a Fig. 103. Fig. 105. single ovule is developed and fills up the cavity of Fedia Fagopyrum. the three posterior confluent cells. The two anterior sterile cells are compressed laterally, until they almost meet in a sharp angle, making the fruit triquetrous like a grain of buckwheat. Between the sharp edges of the angle a narrow groove (103 b, a) runs from base to apex. In a considerable number of matured fruits examined, from W. Penn. and W. N. York, this groove was found uniformly present. All, too, were more or less downy under a lens, and in no case were the sterile cells confluent. These are variations from the typical plant as characterized in Gray's Manual, and yet the peculiar shape of the fruit and its large size (two lines in length) will probably enable it to hold its place as a distinct species. a Fedia a F. radiata, var. Fedia radiata Michx. Fig. 104. Fruit; patellaria. radiata. a, side view; b, cross section, with the two empty cells shaded; c, cross section of another fruit, with the two empty cells confluent. The fruit of this species is much smaller, about a line in length, and usually quite downy, but sometimes smooth.. The quinary structure of the ovary is not so apparent. As in all these Fedias the bracts are more or less strongly ciliated, or perfectly naked. In one particular the description should be amended. Under favorable circumstances it often attains the height of thirty inches, and its range of stature is about that of F. Fagopyrum, one to two feet. Fig. 106. Fig. 107. Fedia radiata Michx., var. patellaria (F. patellaria Sulliv.). Fig. 105. Fruit (from Columbia, Pa.); a, side view; b, cross section, with the two slightly divergent empty cells shaded. This small form varies but little in size a and shape from the fruit of genuine F. radiata as seen in Fig. 104, a and b, and appears to have been derived from it by a mod erate extension of the F. radiata var. patellaria. walls of the empty cells. Fig. 106. Fruit (from Columbia, Pa.); a, side view; b, cross section, with the two widely di- F. radiata, var. patellaria. vergent empty cells shaded. Here the abnormal lateral extension of the walls of the empty cells is carried to an extreme, and they are so flattened in the centre and curved up on the margins as readily to suggest the image of a minia ture platter. This is exactly the form a of fruit in Mr. Sullivant's plant in Dr. Gray's herbarium. Fig. 107. Fruit (from Columbia, Pa.); a, side view; b, end view above; c, cross section, with the empty cells shaded. One specimen of d Mr. Knipe's last collection has this re Fig. 108. markable form of fruit throughout. It F. radiata, var. umbilicata. seems to have been produced by the doubling of that represented in Fig. 106. Two fruits have coalesced by the union of their anterior empty cells, and the dissepiments vanishing have left a single large cell in the middle. On one side the usually fertile cell is empty; on the other, it contains a seed but in some cases all the cells are sterile. Fedia radiata Michx., var. umbilicata (F. umbilicata Sulliv.). Fig. 108. Fruit (from Columbus, Ohio); a, side view; b, another side view, showing the cruciform opening caused by the tendency of the cell in the abnormal expansion of its walls to split along the sutures; c, cross section of the same; d, side view of a more mature fruit, showing a further enlargement of the opening into the empty cell; e, another side view. As the fruit of the former variety came probably from that of F. radiata, with two empty cells, as seen in Fig. 104 b, so this may have been derived, by the operation of the same cause, from that of Fig. 104 c, with the empty cells confluent. In view of the decided disposition toward monstrosity evident in Fig. 107, and the differences of the fruits in size and shape, it is questionable whether F. patellaria and umbilicata are worthy to stand even as varieties of F. radiata; but, since no typical fruits of the latter have been observed intermingled with the aberrant forms on the same stalk, they may for the present be recognized as such. MIMICRY IN THE COLORS OF INSECTS. BY DR. H. HAGEN. HAVING observed that in treating of the interesting phenomena of mimicry, writers have used indiscriminately very different factors, I shall try to give some preliminary ideas which I do not find published, and which I believe will be useful in explaining this interesting subject. It will be best to consider the color and pattern separately. There are three different kinds of colors: viz., colors produced by interference of light, colors of the epidermis, and colors of the hypodermis. All three may either be wanting, or all three, or two of them may occur together in the same place. Colors produced by interference are produced in two different ways; first by thin superposed lamellæ, as in the wings of Diptera, Neuroptera, etc., without any other color, as in hyaline wings, or connected with other colors as in the scales of Entimus and others. There must be at least two superposed lamellæ to bring out |