inhabitants in Prussia. At the same time he maintains that the frequency of the fearful malady caused by echinococcus is much exaggerated-instead of one-seventh, only one-fiftieth of the population is affected, which is quite terrible enough.

PHYSIOLOGY.-Impregnation of the Ovum versus Nourishment of the Larva.-Dr. Herman Landois has recently communicated some important observations on this subject to the French Academy. It is generally believed, in accordance with the observations of MM. Dziergon and von Siebold, that the worker-bees are born from eggs fecundated by the queen by means of the sperm of her receptaculum seminis, whilst drone-bees come from non-fecundated eggs. M. von Siebold maintained, in particular, that the demonstrated existence of spermatozooids in the eggs contained in the "cells' appropriated to worker-bees, and their non-existence in the eggs of drone-cells, sufficiently proves that in bees the formation of the sexes depends upon fecundation. It is, however, well known that the "cells" of drone-bees are not in any way identical with those from which "worker-bees" emerge, and that the food provided for the larvae of the one is not the same as for the larvæ of the other. This led Dr. Landois to speculate as to whether it might not be possible, by placing the egg from the drone-cell into the worker-cell, and vice versa, to produce drones from the workereggs and workers from the drone eggs. This he accordingly tried drone-eggs. with great care, failing at first on account of the exceeding delicacy of the eggs experimented on, but finally meeting with most complete By simply changing the "cell" of an egg, he produced a drone or a worker-bee at pleasure. These observations have a most important bearing on the law of sexual development, not only in insects, but all animals. We had been taught to believe, from Siebold's experiments, that the "network of causes" was so arranged that a queen-bee, if unimpregnated (as might result from paucity of drones), produced from her eggs nothing but drones, in order that the next generation might not be wanting in that "vigour" which is supposed to be the final cause of sexual reproduction. If, however, Dr. Landois' experiments are true, this view must be considerably modified, for the nutrition of the larval animal is shown to regulate the phenomenon. Dr. Landois has entered into some philosophical generalizations on reproduction in the conclusion of his paper, which is not, however, yet published

success.

in full.

Action of Nitrous Oxide on the Human System.-It appears that the protoxide of nitrogen has been used in Germany and France as a means of producing anæsthesia in surgical operations. M. L. Hermann addresses a letter to the French Academy on the subject, seriously urging all operators to make themselves acquainted

with its properties before using it as an anesthetic. He has made several experiments with it himself, and has found that, when respired in a pure condition, protoxide of nitrogen is dangerous; for, besides loss of sensibility, asphyxia is produced, which may kill the patient; administered in a state of mixture with oxygen, the only plan which, in M. Hermann's opinion, would not be simply criminal on the part of the operator, it constitutes a very feeble anaesthetic, from which recovery is rapid. Its use has already produced most serious disasters in Germany.

The Wave-lengths of the Transmission of Muscular and Nervous Action. In a late Chronicle we noticed Dr. Marey's instrument, the Myograph, with which he has been able to make observations on the muscular susurrus-that is, the separate vibrations which, when succeeding each other sufficiently rapidly, constitute a muscular contraction. Dr. Haughton, of Dublin, has been comparing the rate of these vibrations, and their lengths, with those caused by nerve action. Wollaston fixed the muscular susurrus, or agitation sufficient to produce contraction, at from 20 to 30 per second; Dr. Collongues, of Paris, at 35; and Dr. Haughton, as also Helmholtz, at 32 in a second. Dr. Haughton, from the so-called tinnitus aurium, which is caused by the action of the nerves, fixes the rate of nerve vibration at 1,024 in a second. From these data it follows that the rate of nerve action is from 29 to 32 times as fast as the rate of muscular action. Dr. Schelske's experiments have shown that the velocity of wavetransmission of sensation in the living body of man is 97 feet per second; and the experiments of Professor Aebe, of Berne, show that the velocity of wave-transmission of muscular contraction in frogs is 3 feet per second. The wave-transmission in nerves is therefore 32 times as fast (or 29 times, if Helmholtz's determination of 88 feet per second be taken) as the wave-transmission in muscles. It appears, from these facts taken together, that the velocity of the wave varies inversely as the rate of vibration when muscles and nerves are compared, and consequently the length of the wave is constant: hence the wave-length of muscular and nervous action, for both lies between 1.125 and 1·225 inch. Dr. Haughton considers that important consequences ought to follow from this deduction, if true. Many advantages may flow from identity in wave-length of the muscular and nervous force, and the consequent identity of nodes, notwithstanding the very different velocities with which wave-pulses are propagated along them. The data upon which these calculations are made admit, of course, of great extension. Since, as Dr. Marey has shown, the muscular susurrus in the frog may be only 4 per second, and in some birds 75 per second, it would be as well that all the data should be taken from one animal or class of animals, if the calculation

is to be a sound one. It is an assumption, the truth of which ought to be proven, that the rate of transmission of muscular force is the same in all animals.

The Origin of Muscular Power.-The view held by Liebig, and till lately implicitly received as true, that muscular power is due to muscle-oxidation, has been, during the last few months, rudely shaken. Professors Fick and Wislicenus, in an ascent of the Faulhorn in Switzerland, found that the amount of measured work performed in the ascent exceeded by more than three-fourths the amount which it would be theoretically possible to realize from the maximum amount of muscle-oxidation, indicated by the total quantity of nitrogen in the urine. These two observers had, however, to content themselves with the theoretically possible force, and hence there was an experimental gap in their reasoning. This has been supplied by Professor Frankland; he has made an extensive series of experiments on the oxidation of muscle and urea in oxygen, and has made a calorimetrical determination of the actual energy evolved by the combustion of these bodies. His experiments are recorded in full in a late number of the 'Philosophical Magazine,' and the various steps of the very intricate process through which he has successfully carried his observations fully described. Since the oxidation of muscle-tissue in the body has, as one of its products, urea, it is necessary to make allowance for the potential energy of this urea in applying the results of the complete oxidation of muscular tissue to the question at issue. It is also neces

sary to make allowance for the fact that all the energy developed in the body cannot be made to appear as external work. Helmholtz estimates that not more than one-fifth of the actual energy developed can be made to appear as external work; while Heidenhain, under favourable circumstances, allows one-half. Taking this last estimate, Dr. Frankland finds that only one-fifth of the work done by the two professors could be accounted for by the oxidation of their muscular tissue, as indicated by the urine. He further reviews the results of Dr. E. Smith's, Dr. Haughton's, and Dr. Playfair's experiments, applying his determination of the "mechanical equivalent" of muscle-oxidation to their results.

The work done in the body is then evidently due merely to the oxidation of the food held in the blood. The chief use of nitrogenous food is to build up muscle-tissue, which, like the cylinder and piston of the steam-engine, does not contribute to the work performed by its oxidation, but is the means of converting chemical and thermal modes of force into motion; the force being really obtained by the oxidation of principally carbonaceous, but to some extent also nitrogenous, foods contained in the blood.

The Value of Nitrogenous and Carbonaceous Foods.-This question, which is one obviously resulting from the conclusions ar

rived at by Fick and Wislicenus, has been examined experimentally by Professor Pettenkoffer, and more recently also by Dr. Parkes. Professor Frankland has also determined the mechanical value of these forms of food, by experiments on their oxidation. Professors Fick and Wislicenus ate carbonaceous, but no nitrogenous food during their ascent, and hence concluded that all the power not derived from muscle-oxidation was due to the oxidation of the carbonaceous foods. Pettenkoffer's experiments, which are most conclusive as regards the whole question of the source of muscular force, were made by means of a most elaborately constructed chamber, in which a man was placed, and all his excreta, gaseous, liquid, and solid, examined. Dr. Parkes experimented very carefully on two soldiers at Netley Hospital, and communicated his results to the Royal Society at the beginning of this year. Both these observers have fully established that mere force can be supplied by carbonaceous food alonethat nitrogenous food is necessary to build up the worn muscles, and that nitrogenous food, by its direct oxidation, is also efficient in supplying force, and perhaps presents certain advantages over carbonaceous food in its use, either from the facility of its oxidation, or by a catalytic action on the carbonaceous foods with which it is generally taken. The views we have been briefly noticing are of too great importance to admit of their due appreciation from the perusal of so few lines, and we must therefore refer the reader to the original memoirs in which they are advanced. It should be mentioned that Voit, a chemist of Munich, appears to have anticipated these results by some few years; his speculations were, however, cast into obscurity by the proximity of the over-shadowing genius whose assertions they controverted.

MISCELLANEOUS.-Dr. Ernst Haeckel has just published two very remarkable volumes on the philosophy of organic forms, entitled 'The Morphology of Organisms.' He takes much the same line of argument as Mr. Herbert Spencer in his Principles of Biology; but he enters into greater detail, and develops his views further than the English writer. This book, like that of Mr. Spencer, may be regarded as an extension of Mr. Darwin's generalizations, and is, as far as we have been able to observe, a work destined to exert considerable influence in the world of physiophilosophers. We have also to notice a little brochure on Spontaneous Generation and the Development of Infusorial Life,' forwarded to us by Mr. Jabez Hogg. The author has told the story of Heterogenesis (which, by the way, is getting rather old) in a clear and plain manner, drawing attention more particularly to the question of the successive appearance of forms of Infusoria in an infusion, as studied by Mr. Samuelson, Balbiani, and others. There are one or two inaccuracies in nomenclature, such as Acitena; Vor

ticellæ are confused with Rotifers, &c., and a misapprehension is evident of recent observations on the refractive power of fungus-spores, as seen in the "blue-mist;" these errors would be serious in a scientific publication, but do not really affect the value of a popular essay.

PROCEEDINGS OF THE ZOOLOGICAL SOCIETY.

At the meetings of this session there have been numerous valuable papers read, chiefly devoted to the description of new forms or rearrangement of previously known animals. The following papers relate to the Mammalia:-Mr. W. H. Flower, F.R.S., has brought forward a memoir on the skeleton of Inia Geoffroyensis, and on the skull of Pontoporia Blainvillii, in which he made some remarks on the systematic position of these animals in the order Cetacea. Mr. Flower has recently been devoting much time and attention to the study of this order of mammals, as his work published last year by the Ray Society testifies. Dr. W. Peters, of Berlin, made a communication on some Mammalia collected by Captain Bevan in Bermuda, and on a collection of bats from Trinidad. Mr. Gerard Krefft, of Sydney, has described two new species of Dasyurida, which he proposes to call Podabrus Michelli and Chatocercus cristicauda. Mr. Robert Swinhoe, H.M. consul at Amoy, China, has forwarded a new monkey to the menagerie, which he proposes to call Inuus Sanctijohannis. Mr. St. George Mivart, in continuance of his researches on the Primates, has communicated a paper on the appendicular skeleton of the Ourang-Outang, in which he has entered very minutely into the osseous characters of that animal.

Mr. P. L. Sclater described a new species of Ratel, recently added to the Society's menagerie, which he proposed to call Mellivora leuconota. A letter has been received from Mr. E. Bartlett, now engaged in exploring the fauna of Peru, in which he mentions the discovery of a remarkable species of spider-monkey, supposed to be new to science. The death of the sea-bear (Otaria) has afforded an opportunity for the examination and dissection of its viscera, which we believe has never yet been possible. The Society's Prosector, Dr. J. Murie, has been occupied in this task, and some important results may be expected from his investigations.

In Birds, we have numerous new species, or rarer forms, described by Mr. Sclater, and other ornithologists. Dr. Murie has been making some investigations with regard to the Cygnus buccinator, and the new Cygnus Passmori of Professor Hincks, which he considers to be nothing more than a variety of the former.

Dr. Gray and Dr. Günther have described a few new reptiles. The former characterizes a Geckoid lizard from Ceylon, which he proposes to call Gecconella punctata.