tion at the meeting in London on July 5: -Section A.-Mathematical and Physical Science: Seismological investigations, £100; discussion of geophysical subjects, £10. B.— Chemistry: Colloid chemistry and its industrial applications, £5; non-aromatic diazonium salts, £7 7s. 8d. D.-Zoology: Inheritance in silkworms, £17. F.-Economic Science and Statistics: Women in industry, £10; effects of the war on credit, etc., £10. H.-Anthropology: Paleolithic site in Jersey, £5; archeological investigations in Malta, £10; distribution of bronze-age implements, £1; age of stone circles, £15; anthropological photographs, £1. I. -Physiology: The ductless glands, £9. K.— Botany: Heredity, £15; Australian Cycadacem, £17s.; Australian fossil plants, £15. L.-Educational Science: The "free-place" system, £5.

UNIVERSITY AND EDUCATIONAL
NEWS

Ir is officially announced that Yale University will receive, as residuary legatee of the late John W. Sterling, about fifteen million dollars, which will nearly double the endowment of the university.

A SPECIAL three months' course at the New York University and Bellevue Hospital Medical College has been arranged for those who wish to qualify as laboratory assistants in bacteriological work for immediate service in the camps and hospitals. The course is arranged by Dr. William H. Park, director of the laboratories of the New York Health Department, and Dr. Anna M. Williams, assistant director. It will open September 4.

THE College of Physicians and Surgeons of San Francisco has discontinued the teaching of medicine, but will retain a nominal existence for the next three years so as to grant diplomas to such students as shall complete their work satisfactorily in other medical schools.

PROFESSOR M. E. GRABER, fellow in mathematical physics at the University of Chicago, has been elected to the professorship of mathematics in Heidelberg University, Tiffin, Ohio.

DR. E. V. COWDRY has accepted an appointment in the Peking Union Medical College, China.

DR. J. C. WHITTEN, for twenty-four years professor of horticulture and head of the department of horticulture of the University of Missouri, has been appointed chief of the division of pomology of the University of California. Dr. Whitten arrived in Berkeley the middle of August and will begin his work on September 1.

MR. R. DOUGLAS LAURIE, who has been chief demonstrator and assistant lecturer in zoology and lecturer in embryology in the University of Liverpool for some years, has been appointed head of the department of zoology in the University College of Wales, Aberystwyth.

DISCUSSION AND CORRESPONDENCE HAND-MADE LANTERN SLIDES

As well expressed by Dr. Gray in SCIENCE, July 12, 1918, p. 43, it is of advantage and often of the greatest convenience to be able to prepare quickly for projection a series of lantern slides showing diagrams, tabulated data, etc. Dr. Gray suggests the use of celluloid instead of gelatin sheets for this. Both the gelatin and the celluloid sheets must be supported by glass plates to hold them flat. Celluloid and gelatin receive the pen wall, and are far less expensive than regular photographic lantern slides.

It was found by the present writer that for all the purposes of simple diagrams, tables, etc., a still simpler method answers admirably. Advantage was taken of the device employed by the lantern-slide artists who made by hand all the lantern slides before photographic ones were invented (1850). The device consists of varnishing the well-cleaned glass with a very thin solution of some hard varnish. When the varnish is dry the pen or brush can be used upon the varnished surface with the same ease as upon good paper. India ink gives the sharpest images and a fine pen is to be used for the writing or drawing.

In preparing the slides the glass is held by the edges between the thumb and fingers

and the varnish poured on until the surface is covered, then the excess is drained off one corner and the glass is placed in a negative rack to dry. For a varnish, any good, transparent varnish may be used. It should be diluted to about one tenth the usual thickness. For the diluting substance xylene, toluene, turpentine, etc., may be used. Varnish diluted with xylene will dry on the glass in about half an hour if the room is dry and warm. If turpentine is the diluent it is better to let the varnish dry over night.

If the slide is to be used for a single exhibition it need not be covered and bound, but if it is to be permanent it is better to protect the surface by covering and binding as with photographic lantern slides.

If the slides are coated with 10 per cent. gelatin and dried one can also use the pen and brush well, but the varnish has proved a better coating.

These varnished glasses for hand-made lantern slides have been in use in different departments of Cornell University for the last six years and have proved very satisfactory.

It may be well to call attention to the fact that nearly all forms of celluloid are inflammable, and slides made of it might bring disaster.

CORNELL UNIVERSITY, July 30, 1918

SIMON H. GAGE

THE HOUSE FLY

TO THE EDITOR OF SCIENCE: The accompanying paper was written by one of my students in elementary biology within one month of the opening of the course. It happened that the house fly was providing the material for laboratory work at that time. And it also happened that several students were attracted by the inconclusive statements in several textboks regarding the function of the so-called balancers-which they had already recognized as probably representing the second pair of wings. Experiments were thereupon encouraged to clear up the situation. At first results were conflicting, owing to excusable defects in operative technic. Mr. Whealdon,

however, succeeded in reaching unequivocal results, which he embodied in the report that is printed below just as he wrote it.

My purpose in bringing this report to your attention is primarily pedagogical. The facts established by Mr. Wealdon can not lay claim to novelty, as he later discovered. But the method of permitting a student in an elementary course at the very beginning of his work to occupy himself in laboratory hours with a problem he himself had raised and frankly to regard such work as a researchwhich indeed it is in every essential-to be carried to a real conclusion, quite regardless of the activities of the other students in the laboratory; this method, which subordinates prearranged plans by the instructor to the encouragement of student initiative, may be still sufficiently uncommon in American schools and colleges to justify submitting the accompanying evidence of its efficiency.

HARRY BEAL TORREY

THE BALANCERS OF THE HOUSE FLY

Report of Some Experiments to Determine their Use

Experiment 1.-I put two flies of apparently equal vigor, but differing slightly in size and coloring of the abdomen, under the influence of ether. From one of them I removed the balancers by means of very sharp pointed scissors. The other I left untouched, using him merely as a check, by which I could compare the actions of the two as they came out from the influence of the anesthetic. This process I repeated with two more flies, then placed them in pairs, one clipped fly with one unclipped, under bell jars, and observed their behavior.

Through the difference in size and marking I was able to identify the unclipped flies and noted that they appear to recover from the influence of the anesthetic sooner than the clipped flies in both cases. As soon as the flies with the balancers removed recovered from the effects of the ether they commenced to rub themselves with their hind legs, stroking their abdomen and wings almost continuously, even lifting their legs quite above the wings and

pressing them down to the table with a stroking movement. The unclipped flies did not do this, and since they appeared entirely normal I allowed them to escape.

The clipped flies continued stroking their bodies and would not attempt flight except when provoked by being touched with a piece of paper which I pushed under the jar. Then their flight was extremely erratic. They seemed to have largely, if not wholly, lost their power of equilibrium. They would fall upside down, and could pursue no direct flight at all.

As a further test I left them under the jar until the following day and repeated observations with the same results. I again put some normal flies in a jar besides the clipped ones to compare action in flight. The unclipped flies had no difficulty in maintaining an upright position while flying about the jar even though they were striking the sides continuously. The unclipped flies stayed in flight much more, and without provocation.

As a final test I took the clipped flies out of the jars and let them go. Although the movements of the wings appeared entirely normal they could not fly, but fell to the floor with an erratic zigzag movement.

Experiment 2.-The procedure in this case was the same as in the first experiment, except that I used five flies instead of two. For each fly that I clipped I imprisoned another, unclipped, that had been subjected to ether for the same period, to use, as in the first experiment, for comparative study. The five from which I removed the balancers I put under one jar. The other five I placed in a second jar beside the first.

These flies I allowed to remain under the jars overnight in order to recover completely from the effects of the ether. On the following morning I found that one of the flies that had been clipped had died; two of the unclipped had succumbed. Probably the dose of ether had been too great.

Upon testing their powers of flight I found that the clipped flies, just as in the first experiment, were altogether unable to maintain equilibrium. Not one of them when released

could fly at all, but dropped to the floor with a zigzag darting movement. The unclipped flies flew off in normal flight.

Experiment 3.-Having acquired considerable skill at removing the balancers I put a large number of flies under the anesthetic at once. Then from nine flies I removed both balancers and placed them all under one jar. From eight flies I removed one balancer and put them under a second jar; and finally I put seven flies under a third jar. These seven had been subjected to the same dose of ether, but I left them untouched and confined them for comparative study as in the other experiments. The results accorded exactly with those of the other tests.

(a) Flies seemed to notice the removal of the balancers, and kept stroking themselves with their legs about the wings and abdomen.

(b) In no case was a fly with both balancers removed able to fly. They could use their wings, but had no power of equilibrium.

But in contrast to this, the flies with only one balancer removed could fly without difficulty, in a manner to all appearances perfectly normal, although sometimes I thought they had slight difficulty in gaining balance at the commencement of a flight.

From these experiments I concluded that the balancers of the fly are intimately connected with his nervous system, and by a distinct and essential function enable him to maintain equilibrium in flight. But just as a man is not deaf who has one ear injured, nor blind though one eye is destroyed, so this power of equilibrium is not essentially impaired without the removal of both balancers. Submitted November 8, 1917.

ROWAN WHEALDON

QUOTATIONS

THE PROPOSED BRITISH MINISTRY OF
HEALTH

THE Ministry of Health Bill, which has been under the consideration of Sir George Cave's Home Cabinet, will not, we imagine, prove to be a measure as comprehensive and revolutionary as recent debates and discussions might lead the public to suppose. In this connection

we may recall the suggestion put forward last January1 by a group of ten members of Parliament headed by Major Waldorf Astor, now Parliamentary Secretary, Ministry of Food. The group advocated the combination and reorganization of existing departments for the setting up of a Ministry of Health, and submitted the heads of a bill providing that so soon as the new ministry had been established by Parliament all the powers of the Insurance Commissions for England and Wales, and all the powers of the Local Government Board, should be transferred to it by order in council, that the health functions of other departments should be taken over at such times as were found convenient, and that there should be power to transfer from the new ministry to other departments any functions transferred to it at first for the sake of convenience but found to be unsuitable for a health ministry to perform. Under this scheme the new ministry would be simultaneously acquiring and shedding powers, and although the method was recognized to be clumsy, the promoters believed that by this expedient matters of national health would be discussed on their merits undisturbed by conflicting claims of rival authorities. Writing on the subject some four months ago, we said that the indications then were in favor of the government bill being a measure to amalgamate the Insurance Commissions in England and Wales with the Local Government Board, leaving the nonmedical functions of the latter department to be shed at a later date. There is general anticipation that the medical functions of the Board of Education would also be handed over, but with this possible addition the present position appears to be the same to-day as it was in March. If the bill is introduced in this form, it will undoubtedly come in for much criticism. If it means that the Ministry of Health, to quote Sir Bertrand Dawson's words, is not to have "a bigger horizon than the Local Government Board and Insurance Commission, then we must emphatically say 'No.'" On principles, as he said, there 1 British Medical Journal, January 19, 1918,

P. 98.

can be no compromise-" the practise of putting the skilled under the control of the unskilled must cease." One plan for preventing the perpetuation of this evil in the new ministry is outlined in the scheme of the British Medical Association, which proposes the establishment of an Advisory Council of experts. This council should hold regular meetings not less often than once a month, should have direct access to the minister, and should have the power of initiation-that is to say, it should have the right and obligation to tender its advice to the minister on any subject which it considered ought to be dealt with, and not merely on such matters as the minister referred to it. It is proposed to meet the objection that the Board's advice could always be overruled by the minister, acting perhaps under the influence of permanent officials— not experts either in medicine or any of the other professions concerned in the prevention of disease or the maintenance of health-by requiring reports of the Advisory Council to be presented to Parliament. What value this expedient would prove to have in practise is a matter upon which there is room for difference of opinion; but, provided the Minister had efficient permanent medical officials in an independent position of direct responsibility to him, it would undoubtedly afford some safeguard against the risk of "putting the skilled under the control of the unskilled."-British Medical Journal.

SCIENTIFIC BOOKS

The Ornamental Trees of Hawaii. By JOSEPH F. ROCK. Honolulu, published by the author. 1917. Pp. v +210. Illustrated with 79 plates from photographs and 2 colored plates from paintings. $3.50.

One of the charms of tropical cities is the profusion of flowering shrubs and trees. The reviewer has had the pleasure of spending several months in the Hawaiian Islands and can say that Honolulu is the most attractive tropical city he has ever visited. Much of this attraction is due to the wonderful variety and beauty of the cultivated shrubs and trees of the streets, gardens and parks.

Professor Rock has given us descriptions of the ornamental trees and also of many of the larger and more showy shrubs. The trees are arranged in natural sequence beginning with cycads and pines, and ending with Ixora (Rubiaceae).

Probably the most striking street trees in midsummer are two species of Cassia, C. fistula, the golden shower, and C. nodosa, the pink shower. The golden shower (plate 43) has long racemes of golden yellow flowers followed by cylindric woody pods, 20 to 30 inches in length, straight and smooth like a musician's baton. The pink shower (plate 44) has dense racemes of pink and white flowers, a gorgeous sight when in full bloom in June. There is a colored plate of this in Mr. Rock's book.

Another showy tree is the flame tree, Delonix regia (Poinciana regia) (plate 45). This is frequently planted in south Florida, where it is called royal poinciana. The large bright scarlet flowers are in large terminal racemes.

The visitor to the Hawaiian Islands is at once impressed with the number and beauty of the varieties and hybrids of Hibiscus rosasinensis (page 137). In this country the species is sometimes called rose of China. In Honolulu the hibiscus is commonly used as a hedge plant, the large red or white flowers being conspicuous throughout the summer.

Another common hedge plant is a species of the Aralia family (Nothopanax guilfoylei) (page 168). This does not flower in Honolulu, but the white-bordered compound leaves are attractive. The crotons (Codiæum variegatum) (page 128) are common in Honolulu as they are in all warm countries. The narrow leaves are variegated with white and red, in some varieties strongly spirally twisted.

The pepper tree (Schinus molle) (page 132), with feathery drooping foliage and racemes of small red berries, is extensively planted. The plumeria or graveyard flower (Plumiera acutifolia) (page 175), with thick stubby branches, milky juice and white or yellow fragrant flowers, is commonly planted around cemeteries. The flowers are much used for the familiar Hawaiian leis or wreaths made by stringing the corollas on a thread.

One of the most beautifully shaped trees of the parks is the rain-tree or monkey-pod (Samanea saman) (plate 33). The crown is slightly convex and very wide spread. Another member of the Leguminosa is the now thoroughly naturalized algaroba (Prosopis juliflora) (plate 36). This tropical American tree is now common in a belt along the shore of all the islands. The pods furnish an excellent feed for stock and the flowers furnish honey. It is often planted along streets.

Professor Rock has devoted considerable space to the palms, of which many species are cultivated in the parks and gardens throughout the islands. To this group 23 plates are devoted. The commonest and probably the most beautiful of the palms is the royal palm (Oreodoxa regia) (plate 19), the smooth white trunk being very attractive especially when the plants are growing along driveways. The date palm (Phænix dactylifera) (plate 3) is frequent, and the oil palm (Elaeis guineensis) (plate 22) is not uncommon. The fish-tail palm (Caryota urens) (plate 16) is conspicuous because of the great drooping masses of flowers and fruit; the betel palm, because of the tall and very slender stem. Our California fan palm (Washingtonia filifera) (plate 10) is rather frequent.

The visitor to the Hawaiian Islands will find the book very helpful in identifying the cultivated trees. The plates are from excellent photographs and the descriptions give just that information that one wishes to know.

A. S. HITCHCOCK U. S. DEPARTMENT OF AGRICULTURE

SPECIAL ARTICLES

A COMPARISON OF THE RESPONSES OF ANIMALS IN GRADIENTS OF ENVIRONMENTAL FACTORS WITH PARTICULAR REFERENCE TO THE METHOD OF REACTION OF REPRESENTATIVES OF THE VARIOUS GROUPS FROM PROTOZOA TO

MAMMALS1

THE behavior of animals in gradients of intensity of stimuli has long been studied.

1 Contribution from the Zoological Laboratory, University of Illinois, No. 120.