The Religion of Science. By DR. PAUL CARUS. Chicago, The Open Court Pub. Co. 12mo. paper.

In this work Dr. Carus has undertaken to expound what he believes is to be the religion of the future. He disbelieves, as our readers doubtless know, in anything supernatural, but holds fast to the ethical teachings of Christianity and to the Christian ideal of character. It is true that he uses the Divine name frequently; but he expressly teaches that God is not a person, but merely the eternal and all-controlling power in nature. Sometimes he uses the language of pantheism; yet he insists that his doctrine is not pantheism but, as he terms it, entheism. He denies the existence of the soul as a distinct entity, and of course disbelieves in its immortality. Every thing in the old religions that savors of the supernatural he regards as mythology, and maintains that it is destined to pass away, leaving nothing but the moral teachings and aspirations bequeathed to us by the prophets of old. He holds his creed with unquestioning faith, and is rather intolerant of those who still cling to the ancient creeds. "What the Roman church claims to be," he says, "the religion of science is. The religion of science is the catholic and orthodox religion." He is rather bitter against the churches for their adherence to forms and ceremonies and to what he deems erroneous doctrines, and declares that their religion is radically different from that of Christ himself. With much that he says we fully agree, and we respect the moral earnestness with which he discusses the problems of life and duty; but we are not prepared to follow him in rejecting theism, and we have much less confidence than he seems to have in some of the doctrines and criticisms that are put forth in the name of science. Yet we have read his book with interest, and we cordially echo the sentiment he expresses that "blessed is he who trusts in the truth, who hearkens to its behests, and leads a life in which obedience to truth is exemplified."

The work here noticed is to be published with others in a series entitled "The Religion of Science Library," the volumes of which will be issued bi-monthly in paper covers at 25 cents each or $1.50 a year. The first number in the series, which bears the date of September, 1893, is a reissue of Max Muller's Three Introductory Lectures on the Science of Thought," which was noticed in these columns when it first appeared some years ago; and other works new and old will follow in due sea

son.

Heat.

By MARK R. WRIGHT. Longmans, Green & Co., N. Y., 1893, 336 p. 12 mo. $1.50.

THIS text-book of heat and thermodynamics is a wellplanned and well-executed work, suitable for the classes of high schools and colleges in which an elementary course has been given, as introductory to this subject, in the usual first lessons in physics. It is made up with a view to use in connection with instruction in the laboratory, as well as in the lecture-room, and contains an excellent outine of the thermal and thermodynamic principles constituting the modern science of heat, illustrated by experiment, and enforced by numerical examples, not numerous but very carefully selected, and in every case apposite to the text. The book is, in physics, what Remsen's text-book is in chemistry, a well-prepared outline of the theory and experimental method of exposition of the science. The units employed are both the British and the metric, the C. G. S. systems. Students about to take up the applications of such principles in the advanced classes of colleges, and especially of the technical schools, will find this an excellent preparatory course. In the introduction to the chapters on thermodynamics, the work of Rumford and of Davy is given proper place, and more credit is given the former than is usual in earlier treat

ises. Regnault's work is quite fully discussed, and the algebraic treatment of the thermodynamics of gases and vapors is unusually satisfactory. The book is printed on heavy paper, in excellent type, is well illustrated, and well bound.

Outlines of Pedagogics. By PROFESSOR W. REIN. Translated by C. C. and Ida J. Van Liew. London, Swan Sonnenschein & Co.; Syracuse, N. Y., C. W. Bardeen. 12mo. $1.25.

THIS work, by the director of the pedagogical seminary at the University of Jena, is written from the standpoint of the Herbartian philosophy, and is designed to set forth Herbart's theory of education as developed and modified by his disciples. The work, like so many others that come to us from Germany, is not always easy to understand; and, though it contains much that is sound and suggestive, we doubt if it will effect any radical change either in the theory or in the practice of English and American educators. The whole book is written from a German point of view and with reference to German needs; and the division of the school system according to the German division of society into classes is assumed as something final. The parts of the book that are likely to be most interesting to American teachers are those in which the author discusses the end and aim of education and the subjects and method of instruction. The end at which all education ought to be directed is, in Professor Rein's opinion, the formation of character; and he lays such exclusive stress upon the training of the will that he almost forgets that the intellect and the feelings are entitled to consideration on their own account. Nor do we find that he offers anything essentially new as to the means of forming character; for, though he devotes considerable space to the subject, he suggests nothing to the purpose except the study of good literature and the employment of teachers of excellent character. With regard to instruction Professor Rein holds opinions somewhat different from any now prevalent in this country; and, while we cannot endorse all that he says on the subject, there is much in it that is suggestive. He holds, with Comte and others, that the education of the child ought to follow the steps that the race has taken in its historical development; but, notwithstanding the authorities that may be cited in support of this theory, we venture to think that. an education based upon it would be ill adapted to the requirements of a civilized age. The importance of the right method in teaching is a subject on which the author lays great stress, and practical teachers can hardly fail to get from him some hints and warnings that will be useful. The book will serve a good purpose in drawing renewed attention to the importance of moral training, and also by presenting certain aspects of educational work that have not been generally discussed in America. Birds of Michigan. By A. J. COOK. Bulletin No 94, Michigan Agricultural College. 148p. illus. 8vo. THIS Bulletin marks something of a departure in the work of experiment stations. Most of the bulletins issued under the auspices of these wards of the Government are devoted to purely agricultural topics such as feeding of pigs or cows, dairying, planting potatoes, cultivation of corn, value of fertilizers, spraying for fungous or insect diseases and kindred subjects. Some few of the stations publish work of a high character, work which shows some originality. It must be confessed, however; that too much of the station work is of a very poor quality. Often it is a rehash of some previously issued experiments, in which the errors are copied along with the correct statments. Often it consists of descriptions of hastily made experiments which lead to no practical results; or else it may be an account of some experiment which had been tried with negative results years before, but of which the

author of the "new" experiment was totally ignorant. The present publication does not lay claim to any profound scientific knowledge or pretend to herald any new discoveries. It is a catalogue of the species of birds known to occur in Michigan, compiled from various published and unpublished data, with notes on localities and other items. There are 332 species recorded. Abstracts are given of bird and game laws, and a bibliography of over 200 references adds to the value of the whole. The illustrations, mostly taken from Coues's "Key to North American Birds,' will prove of great assistance to those using the Bulletin in the state. J. F. J.

LIQUID AND SOLID AIR.

BY JOHN S. MCKAY, PACKER INSTITUTE, BROOKLYN, N. Y.

THE physical state, or condition, of a body is entirely incidental and never dependent upon any inherent property. The same substance may be solid in one zone and liquid or gaseous in another. According to the kinetic. theory, the different states of matter are only different modes of molecular motion and any change of state is the result of the absorption or liberation of energy. By the addition of sufficient heat energy all solids and liquids become gases, and by withdrawing such energy all gases may be reduced to the liquid or solid state. It is probable that at the temperature of absolute zero (-273°C.) there would be neither solid nor fluid, but that if matter still continued to manifest itself to our senses, it would be in a different physical form from anything now known. It is certain that there could be no gases at that temperature, since molecular motion is essential to the idea of gaseity. From recent experiments it seems probable that all gases, under ordinary atmospheric pressure, would become liquid or solid before reaching absolute zero. It is a well-known fact that after a gas has been cooled below its critical temperature it may be reduced to the liquid state by the aid of external pressure. Until a few years ago oxygen, hydrogen, nitrogen, air, and a few other gases had never been reduced to their critical temperatures and hence could not be liquefied. Air had been compressed until it was denser than water without any trace of liquefaction. And so these gases were called permanent or incoercible gases. But in 1879 Cailletet of Paris and Pictet of Geneva, working independently and by somewhat different methods, succeeded in reaching the critical temperature of some of these gases and by great pressure reduced them to the liquid form. Since then all known gases have been liquefied and the old distinction of permanent and coercible gases has been effaced.

The critical temperature, or absolute boiling point, of these gases is very low, being -140°C. for oxygen, -146° C. for nitrogen, and -240° C. for hydrogen. This low temperature is obtained by evaporating in vacuo liquid NO,CO2, SO,, or some other substance whose critical temperature is comparatively high and which is therefore easily liquefied. As yet hydrogen has been liquefied only in small quantities by allowing it to expand suddenly when at a low temperature and highly compressed. In some remarkable experiments before the Royal Society of London during the past year Prof. Dewar made use of liquid ethylene to secure the low temperature necessary to liquefy air and oxygen. By means of three concentric vessels, the outer one containing liquid nitrous oxide and the next one liquid ethylene, both being connected with powerful vacuum pumps to increase the evaporation, he secured so low a temperature in the inner vessel that oxygen, nitrogen and air were liquefied in large quantities with comparatively little pressure. By causing a vacuum to act upon a large tube containing liquid oxygen, a tem

perature of -210° C. was produced. A small empty testtube inserted into the boiling oxygen was so cold that the air of the room at ordinary pressure condensed and trickled down its sides. By evaporating liquid nitrogen in a vacuum, a temperature of -225° C. was reached, at which point nitrogen became solid.

Liquid oxygen when first formed is milky in appearance, owing to the presence of some impurity which may be removed by passing it through ordinary filter paper. When pure it is of a pale blue color, which, however, is not due, as some have thought, to the presence of liquid ozone, which is of a dark blue color. Liquid oxygen is a nonconductor of electricity but is strongly magnetic. It may be lifted from a cup by presenting the poles of a strong electro-magnet. It seems to have very slight chemical activity, since it will extinguish a lighted match and has no action on a piece of phosphorus dropped into it. It is well known that the A and B lines of the solar spectrum are due to oxygen, and, from recent experiments on the top of Mount Blanc, it is thought that they are largely if not wholly due to the oxygen in the earth's atmosphere. Prof. Dewar showed that these lines come out very strong when liquid oxygen is interposed in the path of the rays from an electric lamp.

Liquid air is at first somewhat opalescent, owing probably to solid particles of carbon dioxide. It may be cleared by filtering or by standing for a few minutes, when the particles rise and disappear. When any of these liquefied gases are placed in an ordinary glass vessel they boil vigorously and soon disappear owing to the heat obtained from the vessel and surrounding objects. In a vessel made of rock salt they take the spheroidal form and last much longer, but Prof. Dewar found that they could be kept longest in vessels with double walls with high vacua between them. A small bulb filled with liquid air and protected by a vacuum would require an hour and a half to boil away, five times as long as it could be kept in an ordinary vessel. Liquid air has the same higt. insulating power as oxygen but is less magnetic. Its magnetic power is evidently due to the oxygen, since liquid nitrogen is not magnetic. When the oxygen is attracted by a magnet it draws the inert nitrogen along with it without being separated, but if a sponge or ball of cotton be saturated with liquid oxygen and presented to a magnet the liquid will be drawn out of the meshes and cling to the magnet until it evaporates. The normal boiling point of nitrogen. is about eight degrees below that of oxygen, so that the two substances may be separated by distillation, the nitrogan boiling off first and leaving the oxygen. But when air is be ng liquefied the nitrogen does not come down first, as might be expected, but the two condense together at a temperature about midway between their respective boiling points.

All the liquefied gases except oxygen and hydrogen have been frozen by self-evaporation in a vacuum. By evaporating liquid air in a vessel surrounded by liquid. oxygen, Prof. Dewar succeeded in reducing the air to a clear, transparent solid. It has not yet been determined whether the oxygen of the mixture is really frozen or merely entangled among the particles of solid nitrogen in some such way as rose water in cold cream, or water in the solid gelatin of calves' foot jelly. Although pure oxygen has never been frozen it is possible that when mixed with nitrogen its freezing point is raised so that the two solidify together.

One of the interesting things connected with these recent experiments in the liquefaction of gases is the fact that it enables us to produce a lower temperature than ever before. We are slowly creeping down toward the absolute zero and the possible solution of the mysteries connected with the nature and constitution of matter. Is

Ir is difficult in a short title to express the leading thought of this paper. Possibly it may be expressed as follows: Fungi, when strictly parasitic, as a rule, infest either a single species, or, if more than one, the hosts are not distantly related. It is therefore to these species that have a wider range than a single sort of host that attention is called at this time. Please bear in mind that the word "strictly" is employed in the statement of the proposition. Therefore it may be possible to draw something of a conclusion from instances when a fungus grows with almost equal ease upon a wide range of substances. But this is a matter of secondary importance at the present time. For our purpose a fungus may be considered strictly parasitic when it attacks what appears to be per

the entire vegetation of the submerged shore, none but the members of the heath family were affected.

The demonstration is quite complete that the presence of this fungus indicates kinship among the host plants. So strong is this that should a new host be found for this gall fungus the first thought would be that the victim is a member of the heath family of plants.

Similar instances might be mentioned in connection with other fungi, and that almost without number. In the case of fungi attacking fruit the circumstances are somewhat different and this sends us back to the word "strictly" in the original proposition. It may be contended with considerable show of reason that a fruit, particularly if it is nearing maturity, is not altogether alive, but instead, having become the receptacle of various substances to facilitate the dissemination of the maturing seeds within, is passing from the condition of a highly vitalized portion of the plant to a passive condition that will soon be on the verge of decay. This being the case, it is not exceptional to the rule when it is found that a mould that grows upon the tomato may thrive equally well upon the peach or plum. The soft tissue in each case is similar and the fungus does not need to overcome the resisting force, peculiar to each species, that is associated with the living portions of the plant. Should the fungus in question grow also upon the other

The

fectly healthy tissue, as the leaf or stem of a plant in the full flush of its vitality. Let some instances be cited to make the fact emphatic. Three years ago there was an outbreak of trouble in a Jersey cranberry bog. leaves, blossoms and young stems became distorted with numerous minute galls, due to a microscopic fungus (Synchytrium Vaccinii, Th.). The cranberry being a bog plant is under water for a part of the year and the shore plants bordering the bog are likewise submerged for some time as well. The fungus discharges its spores into the water, and they are carried to all parts of the bog and the overflowed neighboring land during the spring floods. During the investigation of the cranberry gall trouble the shore plants came under notice, and it was found that several kinds of them were attacked in a way similar to the cranberry. Two interesting facts were obtained in the investigation; first, that the cranberry gall fungus attacked the shore plants up to a certain well-defined line. If the shrub was low it would bear galls throughout, but a high one had them only upon the lower leaves and branches. In short the gall fungus attacked those parts only that were under water at the time of the floods when the spores were being disseminated in the water. The second interesting fact was that all of the shore plants showing signs of infection were all members of the same family (encaciae) with the cranberry. The hosts among themselves are widely different in general appearance, and it was remarkable how dissimilar were the galls upon these various species. Upon the white alder, for example, the galls were large and hairy; while upon the wintergreen and sheep laurel they were smooth. But without going into the details of minute structure there seems no doubt that all forms are of the same species, and while the water must have been well charged with the germs and bathed for days or weeks

wise healthy foliage, of the tomato, peach and plum, the question would be different. It would be a true parasite that was able and willing to flourish upon the fresh products of life, namely, the fruit. The leaf fungi, as a matter of fact, are widely different from those of the peach and plum, and those of the cherry and plum, for example, are often identical; and the hosts are within the same small group.

Passing to a small group of closely related plants; namely, the cucurbits, it is interesting to note how wide spread some of the fungi are preying upon the species. Thus the water melon is frequently badly affected with an anthracnose, which growing in the rind of the maturing fruit causes it to become full of decayed pits. The muskmelon suffers from the same fungus but the texture of the skin of its fruit is so different that the decay might be considered as not the same as the one of the watermelon. third member of the same family, namely the cucumber, is not exempt from the same enemy, as the accompanying engraving will indicate. This illustration is from a photograph of one of a bushel or more of equally bad specimens met with at a market place. The cucumber being of a softer texture is much more quickly destroyed than the muskmelon or watermelon.

A

This anthracnose (Colletstrichum lagenarum (Pass) E and H.) thrives upon the foliage of the three named hosts causing a leaf blight. ing a leaf blight. It is a true parasite and assists in indicating the close kinship of the hosts.

"Our Own Birds," by Wm. L. Bailey, published by J. B. Lippincott Company, is an excellent manual for those who wish to become familiar with the common birds of this country. It contains a number of half-tone full-page illustrations, with others in the text.

CURRENT NOTES ON ANTHROPOLOGY—XXXIII

(Edited by D. G. Brinton, M. D., LLD, D. S.)

OLD SKULLS. AND PERHAPS THAT OF SOPHOKLES.

LAST year, before the British Association, some skulls were exhibited and described, which were of men said to

have lived six thousand years ago. They were brought by Mr. F.inders Petrie from Egypt and taken from tombs of the third or fourth dynasty. They were rather dolichocephalic,-about 75,-and from the general relations of the skeleton, belonged to a somewhat undersized race, with negroid characteristics. They may have been slaves, or a mixed strain.

Not less interesting is the description recently given by Professor Virchow, in the Proceedings of the Royal Frussian Academy of Berlin, of some Greek skulls of ancient date. One of them, from Menidi, was believed by its finder to be that of the great classical dramatist. Sophokles. The oldest were from Mykena, Spata and Nauplia and were prehistoric. They were all slightly brachycephalic, orthognathic, with the nose rather broad. The grave of Sophokles is believed, on a certain amount of literary evidence, to have been on the road from Acharnai, the modern Menidi, to Dekeleía, about 11 stadia from the latter. Following this clue, the archaeologist Mnter opened a tumulus at this point, and came upon a a stone wall enclosing four sarcophagi, two of marble, each containing a male skeleton. One of these was of a very old man, with a cane by his side, an alabaster vase,

etc.

Sophokles died at ninety years of age in B. C. 406, so the character of skull as that of a very old man, corresponds. It proves on examination to be long, 73.3, with a remarkable irregularity between the right and left hemispheres, the left temporal suture nearly obliterated, the forehead broad, the face narrow and high and slightly prognathic, the nose narrow, the capacity low, 1310 c. c. Possibly it is the very skull of the old poet.

THE AFRICAN PIGMIES.

FEW anthropological questions are of so much importance as that of the African pigmies. In the last number of the Zeitschrift fur Ethnologie, Mr. Stuhlmann, who had been with Emin Bey, gives some interesting facts about them. Their height is about 1.25 metres, the head round, the nose flat, the face very prognathic, the hair spiralwoolly and brown, the skin light-brown with an undertone of reddish-yellow. The beard is scant, a light, down-like hair covers the whole body, and the effluvium of the person is penetrating and disagreeable. They differ very much, therefore, from the true negro race.

Mentally, they are cunning, cruel, with keen senses and thieving propensities. They use small bows with poisThey use small bows with poisoned arrows, live in slight temporary shelters, and wear light clothing of leaves or strings. Their language has no numerals, and is related to that of the Wambuba tribes. They appear to have no ornaments, nor to tattoo the skin, but they occasionally bore two holes in the upper lip. They seem to have some religious notions, as they are careful to bury the dead in a particular position. They have some form of marriage, and cannibalism is not general.

Stuhlman does not believe that these dwarfs came about through degeneration, but that they are the relics of a peculiar variety of the human species which once extended over Africa and probably reached into Asia. They have many childish traits, their skeltons are in various respects undeveloped, and they may be regarded as a race of human beings which has undergone permanent arrest of evolution.

This was also the conclusion to which H. Panckow ar

rives in an article published in the Journal of the Berlin Geschaft für Erkunde, in 1:2. He claims that an original diversity is proved by such traits as the e dor of the skin, the development of the gluteal muscles, the smaliness of the hat is and feet etc.

it must be said, however, that these peculiarities are Lly somewhat greater in degree than those of the Bushmen, the Lapps and other dim.Lative rates; and it is not yet necessary to demand for the African dwarfs an origin d.ferent from that of the rest of the human race.

FURTHER ON THE "HITT TE" QUESTION.

Is Sciewe, May 26, I referrel to some recent studies about the so-called "Hittites, or rather, once so-called. but so no longer. The Hittites, as real people, are now determined to have been a Semitic tribe, speaking a dialect not remote from that of Phenicia. They are not the people who wrote the mysterious inscriptions in syllabie characters which still so puzzle the antiquary. These are now referred to as "Pseudo-Hittites, or as before said. Chaidi.

Their language is still unclassified M. Menant claimed to have fixed two of its words, kur, a fortress; and sarou, king; but these are Semitic, so he was off the track. Professor Sayce, in the edition of his "Comparative Philology," published last year, asserts that it "belongs to the Alarodian group of speech, of which the Georgian may be taken as an example;" but Professor Sayce's identifications and translations (?) of the Vannic inscriptions have been treated with small respect by the latest students.

Among such students may be named Lehman, Belck and Nikolsky. The last-mentioned has printed twentytwo Chaldic inscriptions with attempted renderings, in the Proceedings of the Moscow Archæological Society. It is claimed that these determine positively several words, such as ainer, stone; indo, palace; ti ni, named; and a few more. One of the most important inscriptions is that of the styla of Rusas at Toprakaleh, which promises to yield its contents to persistent study.

The present tendency seems to be to regard the Chaldi as of Indo-Germanic origin, probably immigrants from Europe, and their culture largely self developed. Lehmann, in the last number of the Zeitschrift für Ethnologie, gives the credit of first broaching this theory to Professor Puchstein.

ANTHROPOLOGY IN ROME.

IT is a gratifying evidence of the scientific activity. which prevails in Italy, that in June last the Societa Komana di Antropologia was founded at Rome, with a membership of about one hundred founders. The aim of the Society is broad, anthropology being understood in its true sense as the science of man in all departments of his nature. The announcement therefore states that the publications of the Society will embrace papers of the physical traits of man; his origin and pre-history; his ancient migrations; arts and social relations; the ethnic influence of peoples on each other; collective and ethnic psychology and pathology; and the physical and mental education of tribes and nations. The Society is not confined to citizens of Rome, but intends to include those interested in these studies throughout Italy.

The President is Professor Giuseppe Sergi, the distinguished teacher of anthropology in the University of Rome; and among the members are Dr. Angelo Colini, docent in ethnology in the same University; Dr. L. Moschen, docent in anthropology; Dr. E. Raseri, docent in statistical demography, in the same; Dr. E. Brizio, professor of archaeology in the University of Bologna; Dr. V. Grossi, docent in American ethnology in the University of Genoa; Dr. A. Zuccarelli, professor of criminal anthro

pology in the University of Naples; Dr. Riccardi, docent of anthropology in the University of Modena; and many others whose works have secured them well-earned titles of honor.

Professor Sergi himself is one of the most industrious of anthropologists. Within the present year I have seen from his pen a learned essay on the "Principles and Methods of Classifying the Human Race," by craniological forms; a "Systematic Catalogue of the Varieties of Man *found in Russia;" and a Report on the Anthropological Congress in Moscow in 1892. No doubt under his active guidance the new society will have a prosperous career.

NOTES OF SOME EXPERIMENTS ON THE HOUSEFLY.*

BY JOHN B. SMITH, SC. D., RUTGERS COLLEGE, NEW BRUNSWICK, N. J.

INSECTS, in some circumstances, exhibit a tenacity of life which is extremely surprising. They will stand a great deal of mutilation, apparently without manifesting pain, and will get along quite comfortably on a minimum allowance of wings and legs

The house-fly is about as common an insect as we have, and I was led recently to try some experiments with a view to locate, as nearly as might be, the seat of life-or rather the controlling nerve centre, for life exists in each cell-in this insect. A number of flies were captured and decapitated. This process, of course, severed not only the nervous cord, and separated the brain from the rest of the body, but it cut as well the alimentary canal, and the main blood vessel, the Aorta. Flies so treated lived from ten to sixteen hours. They had, of course, lost all sense of direction; but had not lost the use of any of their limbs. When they were touched with the point of a needle they would walk away; but always in a straight line, and without attempting to avoid any obstacle that might have been in the way; if the annoyance was more than a little, they would attempt to fly. As in the former case, they were unable to direct themselves, and as soon as they met with an obstacle would rest quietly until again irritated. So long as they were left undisturbed they remained at rest, or if a pencil was presented to them between the fore legs, they would crawl up for a short distance, and again rest quietly. In such cases it was rather difficult to make them loosen their hold; they would cling tightly, and would not, if they could avoid it, loosen their grasp until something else was presented to them to which they could attach themselves. There seemed to be a realization that something was wrong, and occasionally the front legs would pass over the place where the head ought to be; but there was not at any time what could be considered as a manifestation of pain.

From another set of flies the abdomen was cut. This severed the nervous cord, the heart and the digestive system including in the latter almost all save the œsopha

gus.

These insects lived for from six to ten hours, and for a large portion of the time they were active, flying about and running, and in fact behaving themselves like insects that were in all respects normal. As in the other case there seemed to be no active manifestation of pain. For a short time, say half a hour after the abdomen was severed, the insects were constantly extending and withdrawing the proboscis, evidently realizing that something was wrong, in that connection. At no time was there any interference with the power of motion, either of the legs or wings, and in fact it was impossible to see any difference between their case and those of perfectly normal flies, under the same circumstances and confined with them.

*Read before Section F., at the Madison meeting of the A. A.

A. S.

Perhaps a few words of explanation concerning the gross anatomy of the fly may not be entirely out of place in order that my experiments may be better understood. Insects, generally, have only a single blood vessel, extending the full length of the body, and lying just beneath the dorsum, or upper surface. The digestive system occupies a large portion of the abdomen, and the central part of the thorax. The nervous system extends the full length of the body, in the form of a double cord, on which there are at somewhat irregular intervals enlargements or ganglia, and it lies on the floor of the body, just above the under surface. That ganglion which is situated in the head, is called the brain. We have seen that severing the brain from the rest of the body did not kill the insect; the severed head in no case showed any power of motion in any of its parts, no matter what means were taken to excite it. So long as the head was left attached to the body, even if the abdomen had been cut off, all the mouth parts, and the antennæ could be readily excited and made to move. No insect that had been mutilated by cutting off the abdomen could be induced to feed or attempt feeding. Cutting off all that part of the nervous cord that was situated in the abdomen produced no interference with the powers of motion. From another set of specimens both head and abdomen were removed, leaving only the thorax with its appendages; how much life remained in the abdomen it was impossible to say, since it contained no appendages that could be readily stimulated. The head, as already mentioned, soon died; but the thorax alone retained life for more than six hours, and these fragments of insects could be readily made to walk, although rarely could they be induced to make use of the wings. Yet if one were held up by the legs with forceps, the wings would be used in trying to escape, and would buzz as lively as if the insect was in full possession of all faculties.

From a number of other specimens the abdomen and that portion of the thorax containing the hind legs were removed. These specimens lived for from five to six hours. Both fore and middle legs remained perfectly active, and the mouth parts were readily stimulated. The hind legs could not be stimulated even where that portion of the thorax bearing them remained attached to the abdo

men.

Another set of specimens was treated as were those last mentioned, except that the head also was removed. Here two-thirds of the thorax, containing two pairs of legs, remained alive quite as long as when the head was attached to it; the presence or absence of the brain appearing to make no difference. Other specimens were taken and these were cut in two between the first and second pairs of legs. The anterior p rt, containing the head and fore legs, remained alive for from four to five hours, although of course incapable of moving about. It was easy to induce an insect so treated to extend its tongue, and indeed this was done quite frequently by the insect even without stimulation. The legs were passed at intervals over the front of the head and there was no difficulty in exciting them to motion by merely touching with a needle or any similar instrument. That part of the insect containing the middle and hind legs and the abdomen seemed devoid of active life, and it was impossible to induce these structures, or the wings, to move, within a very few moments after the operation. Another set of specimens was treated exactly as those last mentioned save that here the head also was cut off. In this case the fragment of the thorax containing the front legs lived for three hours, while the other portions of the insect were apparently dead a very few minutes after the operation. An insect cut in half through the prothorax died almost immediately, neither portion responding to such stimuli as I employed, more than a very few moments after.