RECENT LITERATURE.

LANKESTER ON DEGENERATION.'-Mention should have sooner been made of this book, which, with the previously published essay by Dr. Anton Dohrn, draws attention to a phase of development, which has been somewhat neglected of late years; although the French naturalists a generation ago had a good deal to say about arrest of development, retrograde development and retrograde metamorphosis. The author recognizes the fact that there are numerous and important exceptions to the general law of progressive development, that some important groups are due to retrogressive development, or to put it into one word, Degeneration. Lankester explains what he means by degeneration thus: The lizard-like creature Seps has remarkably small limbs, and in Bipes there is only a pair of stumps, representing the hinder limbs. No naturalist, he says, doubts that Seps and Bipes represent two stages of degeneration, or atrophy of the limbs; that they have, in fact, been derived from the five-toed, four-legged or dinary lizard form, and have nearly or almost lost the legs once possessed by their ancestors.

"This very partial or local atrophy is not, however, that to which I refer when using the word Degeneration. Let us imagine this atrophy to extend to a variety of important organs, so that not only the legs, but the organs of sense, the nervous system, and even the mouth and digestive organs are obliterated,— then we shall have pictured a thorough-going instance of Degeneration."

The examples of degeneration given by the author need only to be mentioned, as they are sufficiently striking, and are universally regarded as such. These are the groups of which Sacculina and Peltogaster, Lernæa and Lepas are examples, The Ascidians are regarded as the result of such a process, and their most important stages of degeneration are represented and briefly discussed, though the figure of the larval Ascidian side by side with the tadpole, on p. 42, is greatly exaggerated, a la Haeckel, and is misleading to the lay-reader. The author also speaks of the Ascidians as if they were universally regarded by zoölogists as Vertebrates, whereas they are regarded as Mollusks by some, and as worms by many.

The author considers the antecedents of degeneration to be3: 1. Parasitism; 2. Fixity or immobility; 3. Vegetative nutrition; 4. Excessive reduction in size.

Lankester also regards the sponges as due to degeneration, and "as only somewhat less degenerate we have all the Polyps and

1Nature Series. Degeneration. A chapter in Darwinism. By Professor E. RAY LANKESTER, F. R. S. London: Macmillan & Co., 1880. 12mo, pp. 75. Price, 75

cents.

Der Ursprung der Wirbelthiere und das Princip des Fanctionswechsels. Genealogische Skizzen von Anton Dohrn. Leipzig, 1875. 8vo, p. 87.

See also Cope, Consciousness in Evolution, 1875, and Modern Doctrine of Evolution, AMER. NATURALIST, 1880, 266.

Coral-animals; also the Starfishes." He regards the Lamellibranchiate mollusks as having degenerated from a higher type of head bearing active creatures like the cuttle-fish. The Polyzoa he appears to regard as degenerate mollusks, and the Rotifers as having degenerated from forms provided with legs.

The author then claims that certain human races are degenerated descendants of higher, more civilized peoples; such as the present descendants of the Indians of Central America, the modern Egyptians, "and even the heirs of the great Oriental monarchies of prae-Christian times," while the Fuegians, the Bushmen, and even the Australians may also be degenerate races. Thus while he is indisposed to regard all the human races as degenerated from an early high type of mankind, he recognizes the fact that numerous races have fallen away from a higher stage.

We are inclined to think that the examples of degeneration mentioned by the author are really such. There are other examples not referred to by Professor Lankester, such as the lice and Mallophaga, which are degenerate Hemiptera. Among the Diptera are numerous wingless degraded forms, and when we take into account the fact that nearly all Dipterous larvæ are nearly headless and evidently degenerated forms, we are inclined to think that the entire group of Diptera, numbering at least 20,000 species, are the result of a retrograde development; the Tipulidæ may be an exception, but we were before reading this book disposed to regard the entire order as having degenerated from a lost type, with close affinities to the lower Lepidoptera.

GEIKIE'S PHYSICAL GEOGRAPHY.'-Professor Geikie, the author of this little book, formerly held the chair of geology in the University of Edinburgh, but is now director of the Geological Survey of Great Britain. As an authoritative text book this publication, therefore, needs from us no recommendation; but besides that, it is written in a clear, graphic, attractive style, and the matter is well arranged. We have found the book more useful for teaching purposes than any other. It full enough and readable enough to attract and win the scholar's attention. There are some, though but few, points which in a subsequent edition might be revised; to the Challenger's soundings in the Pacific ocean might be added the results of the U. S. steamer Tuscarora, from San Francisco to Honolulu and Japan, also the results of the U. S. Coast Survey soundings in the Caribbean sea, and the origin and depth off Florida of the Gulf Stream, The author has devoted more space than is usual in similar class-books to the phenomena of the atmosphere, but the treatment of the whole subject is throughout broad and catholic.

1Elementary Lessons in Physical Geography. By ARCHIBALD GEIKIE, LL.D., F.R.S. Illustrated with wood-cuts and ten plates. London and New York, Macmillan & Co., 1881. 12mo, pp. 375. $1.

GEIKIE'S GEOLOGICAL SKETCHES.-This collection of essays, by one of the foremost geologists of the day, not only contains some matter of purely geological interest, but will serve, by the genial spirit and clear, attractive literary style of the author to attract the notice of that large and increasing class in the communityour general readers. The study of geology has gained new interest and fascination in these latter days in connection with biological questions, and from the fact that no tourist can travel through a land and appreciate the nature of its people, without taking into account the qualities of the soil they inhabit. While writerst like Buckle and perhaps Taine have carried to an extreme the independence of man and nature, overlooking the social and moral forces, as well as the laws of heredity; how dependant the making of a people like the English, for example, has been upon the physical geology of Great Britain is well brought out by Professor Geikie in the closing sketch of this book-a chapter which will, perhaps, interest the thoughtful reader as much as any in the book.

Again, fresh attention is being called, especially by some American and Canadian geologists, to the pervasive and powerful agency of so simple a geological agent as rain in eroding lake basins and river valleys; this hitherto not sufficiently appreciated agent having been kept too much in the background by extreme glacialists. The effect on the mind of so good and fair an observer as our author, of the results of atmospheric erosion in the volcanic region of Auvergne in France, bears the strongest and clearest testimony to the past as well as present intensity of pluvial forces, which have done nearly, if not quite as much as plutonic agencies in making our earth what it is.

But none the less is Professor Geikie on proper occasions, a staunch glacialist, and in the interesting record of his Norwegian journeys, we have fresh confirmation by an expert, of the wellgrounded theory that laid ice once capped Scandinavia as well as Scotland, the present representatives being but pigmies compared with the former rivers of ice, which filled and remolded, aided by subglacial streams, the valleys of Northwestern Europe.

In the essay on rock-weathering we have further evidence that it will not do to build public structures of freestone or marble in northern countries like Great Britain or the Northern United States.

Professor Geikie's record of his rapid journey to Montana and the Yellowstone Park, which have been widely read and appreciated, find here a place of permanent preservation, and the stimutus of foreign observation and travel in the mind of one brought up in so small and isolated a geological area as the British Isles,

Geological Sketches at Home and Abroad. By ARCHIBALD GEIKIE, LL.D., F.R.S. Director General of the Geological Surveys of the United Kingdom, with illustrations. New York, Macmillan & Co., 1882. 12mo, pp. 332.

is perceptible in the succeeding chapter on the lava ñelds of Northwestern Europe.

TREAT'S INJURIOUS INSECTS OF THE FARM AND GARDEN.'-One of the most hopeful signs of improvement in agriculture is the increased attention that is paid to injurious insects, the depredations of which have for many years attracted attention from entomologists, have at length forced themselves upon the notice of legislatures, and are now at last beginning to awaken the agricultural mind to the importance of the study of the life-history of the pests, with a view to combating them. In the words of the author, "There is a surprising lack of knowledge among otherwise well-educated people as to the life-history of even the most common insects. The question asked not only by those in my immediate neighborhood, but by letters from all parts of the country, show how slight is the popular knowledge on this most important branch of Natural History." Too true-even a nonentomologist finds himself surprised at the vastness of the ignorance, yet the mere asking questions is a great advance upon the state of mind that referred a plague of caterpillars to the providence of God.

In the two hundred and eighty pages of this little book all those insects that have developed into conspicuous pests are figured and described in terms sufficiently simple for the comprehension of any reader who is able to discriminate an insect from a spider or a myriapod, or the orders of insects from each other. That readers in search of knowledge may be without excuse, the author prefaces her work with information on the above essential points.

The subject is dealt with under the heads of, Insects injurious to Garden Vegetables; Insects injurious to Root Crops and Indian Corn; Insects injurious to Cereal Grains and the Grass Crops, including Clover; Insects injurious to Fruit Trees; Insects injurious to Small Fruits, and Insects of the Flower Garden and Greenhouse. In many cases methods of extermination or at least of palliation, that have previously proved successful are detailed, but, as is remarked with respect to the pea-weevil, in order to exterminate an insect from a district it is necessary that agriculture shall have progressed to such a point that all the farmers of a district shall mutually agree to carry out the proper measures in unison; in the case of the last-mentioned insect, such a result would be arrived at were all to cease the cultivation of peas for a simple year-a cheap price for the benefit accruing. Among facts not very widely known are the destruction wrought among cabbages, by Plusia brassica, Riley; and that caused on parsley, carrot, and other cultivated umbellifers by the

1Injurious Insects of the Farm and Garden. By MARY TREAT. Fully illustrated. New York, Orange Judd Co., 751 Broadway. 1882.

green, black-and-yellow-spotted caterpillers of the beautiful black yellow-spotted swallow-tail butterfly.

The Lepidoptera and Coleoptera take the lead in the number of destructive species, and it is hard to say which works most damage, as most of our cultivated plants appear to have enemies in both ranks, though the potato and sweet-potato are especially affected by beetles, and the cabbage and fruit-trees generally, by caterpillars. The Hemiptera, with Phylloxera, the Chinch-bug and the aphides, come next in destructive powers; the Diptera contribute several species, the Hymenoptera, though principally beneficial to man, furnish him with saw-fly enemies; and the one destructive locust enumerated is a host in himself. The work is printed in clear type and forms in all respects an attractive volume. —W. N. L.

U. S. FISH COMMISSION REPORT FOR 1879.-This stout volume is full of good material, whether piscicultural or zoological or botanical. Several excellent papers, purely scientific and yet of value in the connection in which they appear, are sandwiched in between the commissioner's own report and the chapters relating to fish-culture. The most important of these, and abundantly illustrated with excellent wood-cuts, are Professor W. G. Farlow's Marine Alge of New England, and Professor A. E. Verrill's report on the Cephalopods of the north-eastern coast of America. A large proportion of the volume is devoted to translations from European authors, which will undoubtedly prove useful to pisciculturists in this country, though there are chapters by H. W. Mason, Livingston Stone and Charles G. Atkins on the propagation of salmon. These reports are doing great good in both a practical and scientific direction.

RECENT BOOKS AND PAMPHLETS.-A system of Human Anatomy, including its medical and surgical relations. By Harrison Allen, M.D. Section 1. Histology, by E. O. Shakspeare, M.D. Section II. Bones and Joints, by H. Allen, M.D. Philadelphia, 1882. From the author.

United States Commission of Fish and Fisheries. Report of the Commissioner for 1879. Washington, 1882. From the department.

The Mungoose on sugar estates in the West Indies. By D. Morris, M.A. Kingston, Jamaica, 1882. From the author.

Official Report on the Creston group of mines in the State of Durango, Mexico. By Frofessor Adolphe Rock. Philadelphia, 1882.

On Fishes Tails. By E. T. Newton, F.G.S. Reprint from the Journal of the Quekett Microscopical Club. London, 1882. From the author.

Camps in the Caribbees. The adventures of a naturalist in the Lesser Antilles, By Fred'k A. Ober. Boston, 1880.

Thèses présentées a la Faculté des Sciences de Lille, Université de France, pour obtenir le grade de Docteur ès Sciences Naturelles. Par Persifor Frazer, A.M., de Philadelphie. Ire Thèse: Memoire sur la Geologie de la parti sud-est de la Pennsylvanie. 2me Thèse: Propositions donneés par la Fucultè. Lille, 1882. From the

author.

Report of Proceedings of the National Academy of Sciences, from Nov. 16, 1880, to the close of the year 1881.