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REVIEWS.

THE ORIGIN OF GENERA.* -- In this essay the author does not consider that generic and specific characters are identical. He divides animals into numerous series, specific, generic and so on, in which the lower members of each form the progressive steps, with the exception of course of the specific series. “The lowest or most generalized terms or genera of a number of allied series, will stand to each other in a relation of exact parallelism. That is, if we trace each series of a number, up to its lowest or most generalized genus, the latter together will form a series similar in kind to each of the sub-series, ¿. e., each genus will be identical with the undeveloped conditions of that which progresses the farthest, in respect, of course, to the characters which define it as a series.” Cases of exact parallelism are accounted for by the law of “retardation and acceleration,” which is claimed to be “a continual crowding backwards of the successive steps of individual development, so that the period of reproduction" "falls later and later in the life history of the species, conferring upon its offspring features in advance of those possessed by its predecessors."

Prof. Cope here points out a parallel between the development of the individual and of the genus of great interest and novelty. “As one or more periods in the life of every species is characterized by a greater rapidity of development (or metamorphosis) than the remainder, so in proportion to the approximation of such a period and the epoch of maturity or reproduction, is the offspring liable to variation. During the periods corresponding to those between the rapid metamorphosis, the characters of the genus would be preserved unaltered, though the period of change would be ever approaching." "As the development of the individual, so the development of the genus. We may add so the development of the whole of organized beings.”

After stating that as a rule animals exhibit in course of development certain specific, before they do generic, characters, the author says:

Apart from any question of origin, so soon as a species should assume a new generic character, it ceases, of course, to be specifically the same as other individuals which have not assumed it. If supposed distinctness of origin be, however, a test of specific difference, we shall then have to contend with the paradox of the same species belonging to two different genera at one and the same time.” Several instances then are brought forward to prove the proposition “that the nearest species of adjacent genera are more nearly allied in specific characters than the most diverse species of the same genus,” and, also, that like varieties of distinct species are much nearer in shape and appearance than unlike varieties of the same essential species.” In course of time a series is formed in which

• The Origin of Genera. By Prof. E. D. Cope. Philadelphia. 8vo, pp. 80. $1.25.

the adult characteristics of the original genus are reduced to a larval condition, but the original genus still continues to "accelerate” its own development, though more slowly, and finally reduces its original characteristics also to a larval condition, and acquires in the adult state different characteristics from the first series.

This, with other confirmatory evidence, renders it probable that generic changes may simultaneously take place in a number of species without the loss of their specific characteristics, and in the same way genera may be simultaneously transferred from one suborder ts another without the loss of their generic characteristics. The development of generic characteristics thus appears to be governed by a law which is not dependent upon physical surroundings. Species on the other hand, though they “exhibit a proportion of characters which are the successive stages of that one which progresses farthest,” yet “the majority of specific characters are of divergent origin, — are.“morphic as distinguished from developmental.” Thus specific characteristics are essentially, adaptive, and therefore due mainly to natural selection. The author's conclusions are given in six propositions, from which we quote the two given below:

I. Species have developed from preëxistent species by an inherent tendency to variation, and have been preserved in given directions and repressed in others, by the operation of the law of Natural Selection.

II. Genera have been produced by a system of retardation or acceleration in the development of individuals; the former preëstablished, the latter on preconceived lines of direction. Or in other words, while nature's series have been projected in accordance with the law of acceleration and retardation, they have been limited, modified and terminated by the law of natural selection, which may itself have operated in part by the same law.

AN ILLUSTRATED WORK ON THE BUTTERFLIES OF NEW ENGLAND. Mr. Samuel H. Scudder will publish during the coming winter, a large and expensively illustrated work upon New England Butterflies. He will give, as far as possible, a complete history and description of each species during every stage of its existence; tables and descriptions of genera will be introduced, together with a preliminary chapter upon the general structure of butterflies, which will serve as a guide to their careful study; their geographical distribution, both in and out of New England, will be largely discussed, and the book virtually form a manual for all the Northern United States; it will be generously illustrated by colored plates of every species, done in the highest style of the art.

To make the work as complete as possible, the author invites the assistance of entomologists in obtaining living or fresh specimens of eggs, larvæ and pupæ, for illustration and study. Without such assistance it would be impossible, in a single summer, to obtain all the requisite material. Full credit will be given in the book for every item of assistance rendered.

The success with which Mr. Saunders, of Canada, has reared butterflies in their earlier stages, ought to encourage our friends to similar efforts. Mr. Saunders' method is to confine each female butterfly in a small, dark box, - a pill box for example, -in which she is obliged to deposit her eggs; he endeavors, before the eggs are hatched, to notice what plant the butterfly seems to affect; the young larvæ are fed upon it, and, iu many instances, successfully reared.

As careful descriptions of these larvæ and pupæ cannot be prepared without many specimens, and as we have so little accurate knowledge of the earlier stages of our native butterflies, our friends need not fear to send Mr. Scudder all the specimens they can find. If possible, they should be sent alive, so as to secure good colored drawings of each species; the larvæ should be accompanied by fresh, moistened leaves of their food plant for nourishment on the journey, and forwarded by mail in small, light, but strong boxes (tin is preferable), to S. H. Scudder, Boston Society of Natural History, Berkeley street, Boston, Mass., marked in addition, Insects. This latter precaution is necessary, because, in case of a temporary absence from the city, Mr. Scudder will leave directions to have boxes thus marked, sent at once to his artist. The specimens should be accompanied by the name and address of the sender, and, when known, the name of the insect and of the plant on which it feeds. When it does not seem practicable to forward them alive, they may be sent in small bottles of glycerine, or in a mixture of one part pure carbolic acid (Squibb's preparation), and twenty-four parts water. In this case also they should be sent at once and by mail, that the colors may be seen before they fade. When neither of these methods is possible, spirits may be used, but the colors will soon be lost. If any one obtains a number of eggs and is able to raise them, it would be best to forward, from time to time, two or three specimens both of the eggs and chrysalids, and the same number of each moult of the larva; the butterfly which has laid the eggs should always be preserved, and forwarded with the larvæ, etc., for satisfactory identification. If any one is in doubt about the food plant of some insect which he has found, it would be best to write a letter of enquiry to Mr. Scudder, who will be glad to answer any questions.

Those willing to assist in this work should commence at once to trace the history of the Theclæ and Lycænæ, of which almost nothing is known. The former feed upon various trees and shrubs, such as the oak, thorn, willow, pine and cedar, and also on the hop-vine; the latter upon different kinds of herbs, as Lespedeza, etc.

The author trusts that those who live outside of New England, will remember that he must depend absolutely upon them for information concerning the earlier stages of those insects which are very rare in New England, but common with them. Any assistance that they can render him will be most gratefully received.

THE KINGFISHERS. — A monograph of this beautiful family of Birds is now being published by Mr. R. B. Sharpe, of the Zoological Society of London. It will be issued in twelve to fourteen parts, imperial 8vo, each part to contain eight beautifully colored lithographic plates. All the species of Kingfishers known (about one hundred) will be described and figured, and Dr. Murie will furnish a chapter on the anatomy and osteology of the family. Only two hundred copies of the work will be printed: three parts are already issued. The price to subscribers will be about $5.00 a part, delivered in this country. The work is worthy of support by the ornithologists of this country, and we should be happy to take subscriptions for the author. The price will be advanced one-fifth after the work is out.

BULLETIN OF THE ESSEX INSTITUTE.* — This new publication of the Institute is one of the results of the changes that have taken place owing to the formation of the Peabody Academy of Science, and the transfer of the Scientific Museum of the Institute to the charge of the Academy. In great part the “Bulletin” will take the place of the “Proceedings and Communications” of the Institute, which will be discontinued after the publication of Volume six (now in press), which will bring the Proceedings up to the month of January, 1869, at which date the “Bulletin” commences.

The “ Bulletin” will contain an account of the proceedings at each meeting of the Institute, and the lists of donations, etc., made to the library of the Institute, and to the Museums of both the Institute and the Academy. It will also contain short lists of the deficiencies in the library of the Institute, and of duplicate books offered for sale and exchange, but by far the greater part of each number will be devoted to the short communications read at the meetings, and of general interest, while the longer historical papers will be printed as heretofore in the “Historical Collections," and the purely scientific communications will be offered to the Academy for publication in its Memoirs. It will thus be noticed that the “Bulletin” will take the place of the “Proceedings,” while the Memoirs of the Academy will correspond to the former “Communications" of the Institute.

The first number of the “Bulletin” contains, among other interesting papers, the remarks made by Prof. A. M. Edwards at a recent meeting. on Guano, in which Prof. Edwards advances the theory that guano is not the droppings of birds, as has generally been supposed, but is the deposit of the remains of dead animal and vegetable matter at the bottom of the ocean, which, as the coast rose, had been so lifted as to appear on the crests of the islands formed, and from the chemical changes it had undergone, had become guano. Among other facts brought forward to prove his theory, he mentioned that an island had risen at the Chincha group, which contained guano on its summit at the time of its uprising. He also alluded to the fact that the droppings of birds would be quite inadequate to supply the vast amount of guano found, and that such droppings were chemically distinct from guano.

The first and second numbers of the “Bulletin" contain obituary notices of our late associate, Horace Mann, and of the distinguished ornithologist, John Cassin.

*8vo, 16 to 20 pages. Issued monthly. Price 10 cents single copy. Subscription $1.00 a year, Essex Institute Press.

THE CRANE-FLIES OF NORTH AMERICA.* - Another of the useful entomological works issued by the Smithsonian Institution, is Baron Osten Sacken's elaborate Monograph of the North American Tipulidæ (or Craneflies), with short palpi, comprising the smaller species of the family; the true Tipulids comprising the well-known crane-flies so abundant in our gardens and fields. This work, destined, we judge, to be a classic in American entomological literature, is useful not only as containing descriptions of all our known crane-flies, but as a model of the mode of monographing a group of animals; and for patient research, thorough treatment and the new mode of illustration (heliographs by Egloffstein's patent) is one of the most important works on insects published during the past year in any language. It will be noted at greater length in the “Record of American Entomology” soon to be published.

REVISION OF THE LARGE, STYLATED, FossoRIAL CRICKETS. - In the first number of the Memoirs of the Peabody Academy of Science, † Mr. S. H. Scudder has brought under review all the species of the palmated crickets known to him, with the exception of the smaller forms. The descriptions of the species are carefully prepared, and each description is accompanied with a full table of measurements of several specimens. The plate contains a full-sized figure of Gryllotalpa australis, from New Holland, a species never before figured; and thirty-seven details of forelegs and wing-covers of the different species.

The author has prefaced his own descriptions with a full list of the various writers on the group, with remarks on the species mentioned by each. The Mole Crickets which are furnished with but two dactyls on the fore tibia, he places together as forming a new genus, to which he gives the name of Scapteriscus, while for those having four dactyls, he retains the old generic name of Gryllotalpa.

THE Noxious INSECTS OF Missouri.f—This first report of the State Entomologist is exceedingly creditable both to the author and the State which has so liberally fostered the study of economical entomology. Farmers and gardeners throughout the country will find it a very readable book, and entomologists will glean many new facts from its pages. The chapter on Cutworms, Bark-lice, the Plum-curculio, the Seventeen-year Cicada, the Potato-beetles and the Bot-fly of the sheep, are of especial interest.

We learn that the State of Missouri has acknowledged the value of the study of practical entomology, by the appropriation of $3000 to pay the salary of the Entomologist for the present year. In such a liberal provi

Monographs of the Diptera of North America, Part. IV. (Smithsonian Miscellaneous Collections, 29). Prepared for the Smithsonian Institution by Baron Osten Sacken. Washington, Jan., 1869. Svo, pp. 345, 4 plates.

+ Imperial 8vo, 32 pages and steel plate; tinted paper. Salem: Essex Institute Press. March, 1869. Price $1.25.

* First Annual Report on the Noxious, Beneficial and other Insects of the State of Missouri. By Charles V. Riley, State Entomologist. Jefferson City, 1869. 8vo, pp. 190, with two colored lithographic plates and ninety-eight cuts, $2.00; with plain plates $1.00.

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