waters. The Echinodermata, described by Grieg, include 2 crinids, 6 starfish, 6 ophiurids, strangely only 1 sea urchin, and 4 holothurians. The rest of the described marine fauna consists of 2 sponges, 4 actinians, 6 sea-squirts, 10 hydrids, 4 medusa, and 44 kinds of polychaete worms. Clearly Arctic waters do not teem with a variety of animal life, but they make up for this in abundance of individuals. The geologic results of Per Schei are very rich, not only in the abundance and variety of fossils gathered, but also in the record of the distribution of the various formations. Over the Archeozoic granites of Ellesmere Land lie about 14,000 feet of Paleozoic strata, beginning with Upper Cambrian, followed by basal Ordovician (Beekmantown), middle Ordovician, early and middle Silurian, and an extraordinary development of Devonian, having a thickness of about 6,000 feet (marine Lower and early Middle Devonian and an Upper Devonian fresh-water facies). The Carboniferous is known only in highest Pennsylvanian rocks, followed by marine Upper Triassic. Then there is no sedimentary record of any kind until the deposition of the Miocene fresh-water beds with lignites. As Per Schei died soon after the return of the expedition, the fossils are described by O. Holtedahl in three papers, one of which gives a summary of the geological results attained. The land plants of the Upper Devonian and the very few from the Miocene are described by A. G. Nathorst; the Devonian fishes by J. Kiær; the Devonian invertebrates by O. E. Meyer and S. Loewe; the Upper Carboniferous fauna by T. Tschernyschew and P. Stepanow; and the Triassic marine invertebrates by E. Kittl. From Per Schei's account and the splendid photographs (the best Arctic pictures anywhere), it is evident that Ellesmere Land is an elevated and dissected table land, rising directly toward Greenland. Elevated strandlines and wave-cut terraces are seen along most shores, and are of various altitudes up to 570 feet. On one at 300 feet lie undecomposed driftwood and logs, attesting the recentness of some of this elevation. Norsemen are still lovers of heroic work, and the north lands are their special scientific field. From them we are learning the geography, geology, and biology of the lands of the midnight sun on either side of Greenland, the territory of the Danes. We need, however, still more information about these almost inaccessible places, and let us hope that the Norwegians will soon extend their endeavors and modernize our knowledge of Nova Zembla. CHARLES SCHUCHERT SPECIAL ARTICLES IN the various experiments on animals in regard to growth, nutrition, activity, reproduction, etc., it is necessary to determine the age of the individuals at various times in their lives. These computations, involving mere additions and subtractions, take a great deal of the experimenter's time. The task is monotonous and soon becomes a matter of great drudgery. Having before me the task of making several thousand such computations I sought a means of obtaining this data in a quicker and less tedious manner. The instrument described and used by Minot in his work on the guinea pig appealed to me. It had, however, the objectionable feature that the age of but one animal could be ascertained at a time. As I was dealing with a pair of animals whose weights were made on the same day and whose ages were to be determined when litters were born it was necessary to devise a scheme whereby the ages of two individuals born on different days could be readily determined at various times in their lives. The device finally hit upon is so simple to make and operate that I have deemed it worthy of a description in order that others who may be wrestling with such tedious computations may be relieved of their drudgery. The device consists of three meter sticks, M, A, and F, with two guides, G, G. The middle meter stick and the two guides are fastened securely to a board and the other two meter sticks slide freely. To facilitate movement a small knob, K, is screwed to each of the movable sticks. A slider, S is made like a small T-square. It crosses the sticks at a right angle and can be moved freely along them. The two guides are slightly thicker than the meter sticks so that the movement of the slider does not change the position of the movable meter sticks. M is used in determining the age of the male and F that of the female. For the sake of simplicity the millimeters are not shown in the figure. The method of using this device is best illustrated by an example. Suppose the male of a pair was born on April 10, 1919, and the female on February 19, 1919. The first date is the 100th day of the year, and the second date is the 50th day. A calendar having all the months of the year on one page and also having each day in the year numbered consecutively from both the beginning and the end of the year is used for determining what day in the year a certain date represents. Stick M is moved until its right end is even with the 100-millimeter mark on A and F is similarly moved to the 50-millimeter mark. If a weighing were made on June 9, 1919, which is the 160th day of the year, the slider is moved to the 160-millimeter mark on A. The age in days of each animal is now indicated on their respective sticks by the number of millimeters to the right of the slider. That is, the male is 60 days old and the female 110. If the age is to be computed on November 27, 1919, the 331st day of the year, the slider is moved to 331 on A and the age of each at once read off, which is 231 and 281 days respectively. The ages at any date in 1919 can thus be computed without moving anything but the slider. If a date occurs in the succeeding year, 1920, then the sticks would require resetting. This is done in the following manner. The slider is moved to the 365 mark on A, which represents the last day of 1919, and the readings taken on M and F. These are 265 and 315 respectively, that is, the ages on December 31. These two numbers may also be found on the calendar since they are the days in the year when numbered consecutively from December 31 to January 1 corresponding to the two dates of birth. M is now moved to the right until its 265 millimeter mark is even with the end of A and F is moved in a similar manner until its 315 mark is even. This arranges the instrument for any date in 1920. If the ages are desired on March 28, 1920, the 87th day of the year, the slider is moved to 87 on A and the ages of the two animals are at once indicated as 352 and 402 days respectively. In this man ner the ages may be rapidly determined for any date desired. It is obvious also that the device can be arranged to give the ages when the two animals are born in different years. The limit of capacity of this device is 1,000 days. But in dealing with animals with a longer span of life each millimeter can represent a week, a month, or a year and the ages computed in these periods of time. The excuse for this article is the hope that it may help some one who is confronted with a series of tedious computations similar to the ones with which I have had to contend. J. ROLLIN SLONAKER PHYSIOLOGY Department, STANFORD UNIVERSITY THE CLASSIFICATION OF THE OPALINIDE I HAVE Completed a study of one hundred and thirty-four species and twenty subspecies which according to the prevalent usage would be included in the genus Opalina. Twentyfour species were known before. My material, obtained mostly from the United States Na tional Museum through the great kindness of Dr. Leonhard Stejneger, is thoroughly representative for the whole western hemisphere and includes many forms from all other parts of the world, Africa, Europe, temperate Asia, the East Indies and Australia being well represented. Southern Asia is the only region from which there is but little material. Clear presentation of the taxonomic conditions shown in the rather large amount of data necessitates a more elaborate classification of the Opalinide than that generally in use. In the year 1918 I published a classification of the Opalinidæ. The completed review of all the material shows that this classification, if elaborated somewhat will be a clearer expression of the real facts. I therefore now propose the following classification: The Opalinidæ are placed as an appendage of the Ciliata, being separated from the other Ciliata by the fact that they have not developed macronuclei and micronuclei, and by some features of their life history. They show, both in their structure and possibly in their life history, decided indication of relationship to the Trichonymphide which are usually regarded as an appendage of the Flagellata. From the Opalinidæ I exclude all the genera of Ciliata astomata, which have nuclei of two sorts, leaving, only those forms which, with the exception of my own recent usage, have been included in the genus Opalina. The Opalinidæ include both binucleated and multinucleated species and these should be assigned to distinct subfamilies. The Protoopalininæ include the genera Protoopalina (cylindrical binucleated forms) and Zelleriella1 (flattened binucleated forms). The Opalininæ also include two genera, Cepedea2 (cylindrical multinucleated species) and Opalina (flattened multinucleated species). The latter genus includes two groups of species-the western hemisphere forms, which are for the most part narrow, especially posteriorly, and the eastern hemisphere species, all of which are broad. All the other Ciliata may be classed as Euciliata in distinction from the Protociliata which include only the Opalinidæ. There are two species which do not accurately fit into this classification as defined. They are Protoopalina quadrinucleata from Rana macrodon of Java and Protoopalina axonucleata from Bufo bufo asiaticus of eastern Asia. These species will be described in a paper soon to go to press. They are mentioned here merely because the former usually has four nuclei and the latter usually shows six to twelve nuclei. They are transitional forms between the genera Protoopalina and Cepedea, but are classed with the former genus because of the histological character of their nuclei which resembles that of the Protoopalina nucleus. MAYNARD M. METCALF THE ORCHARD LABORATORY, THE OHIO ACADEMY OF SCIENCE THE thirtieth annual meeting of the Ohio Academy of Science was held at the Ohio State University, Columbus, May 14 and 15, 1920, under the presidency of Professor F. C. Blake. Sixty-nine members were registered as present; thirty new members were elected. The executive committee reported the completion of the affiliation of the academy with the American Association for the Advancement of Science in accordance with the plan adopted by the association at the Christmas meeting. 1 Named for Ernest Zeller who in the year 1877 published a fine paper upon the European species of the family. 2 Named for Cassimer Cepede whose studies upon Ciliata astomata clearly showed that the Opalinidæ are to be regarded as quite distinct from the other astomatous forms. It was reported by the trustees of the Research Fund that Mr. Emerson McMillin, of New York City, had made a further contribution of two hundred and fifty dollars to the research fund. In view of his continued financial support of the research work of the academy Mr. McMillin was elected a patron; he was also elected to fellowship in the academy on the strength of his own contributions to science. The following special resolutions were adopted by the academy: 1. Recording appreciation of the work of the Ohio Biological Survey and expressing the hope that its work, now financially crippled, may be continued with increased support. 2. Urging the utmost watchfulness in the conservation of platinum and condemning its use "in jewelry and in any other way that is not productive of scientific or industrial advance or development.' 3. Urging a like conservation of potassium and the use, wherever practicable, of sodium salts as a substitute for potassium salts in scientific and commercial work. 4. Endorsing the work of the State Department of Agriculture in establishing preserves for game and other wild life of the state, and appointing a committee to cooperate in this work. This committee, under the chairmanship of Professor Herbert Osborn, of Ohio State University, is in posi tion to cooperate also in the nation-wide movement in this direction instituted by the Ecological Society of America and endorsed by the American Association for the Advancement of Science. Officers were elected as follows: President, W. H. Alexander, Weather Bureau, Columbus; Vicepresidents: Zoology, F. H. Krecker, Ohio State University; Botany, C. H. Otis, Western Reserve University; Geology, W. H. Bucher, University of Cincinnati; Physics, D. C. Miller, Case School of Applied Science; Medical Sciences, Ernest Scott, Ohio State University; Psychology, H. A. Aikins, Western Reserve University; Secretary, E. L. Rice, Ohio Wesleyan University; Treasurer, A. E. Waller, Ohio State University. The scientific program was as follows: PRESIDENTIAL ADDRESS The Einstein theory of relativity and gravitation: PROFESSOR F. C. BLAKE, Ohio State University. PUBLIC LECTURE Photographing sound waves from large guns and projectiles: PROFESSOR DAYTON C. MILLER, Case School of Applied Science. SYMPOSIUM BEFORE PHYSICS SECTION The constitution of the atom: (a) The planetary atom of the physicist: S. J. M. ALLEN; (b) Why not one kind of atom only? R. C. GOWDY; (c) Discussion led by W. L. EVANS. PAPERS The Arizona boll weevil (Anthonomus grandis var. thurberia) with special reference to steps taken by the Arizona Commission of Agriculture and Horticulture to prevent its establishment in cultivated cotton: DON C. MOTE. Aphelopus theliae (Gahan) and the changes produced in Thelia by this parasite: S. I. KORN HAUSER. The intestinal parasites of overseas troops as compared with home service troops: S. I. KORN HAUSER. A new disease, black tumor, of the catfish: R. C. Osburn. Classification of the Opalinidae: MAYNARD M. MET CALF. Geographical distribution of the Opalinidae: MAY- Factors in the distribution of aquatic snails in Notes on some tropical Homoptera: HERBERT OS BORN. Generic and specific characters from the male genitalia of Syrphidae (Diptera): C. L. METCALF. Some myriapods of Put-in-Bay: STEPHEN R. WIL LIAMS. Claws of arachnids: W. M. BARROWS. KINDRED. Additions to the birds of Ohio: LYNDS JONES. Two recently destructive clover insects of western The preservation of native flora and fauna: HERBERT OSBORN. New economic applications for the mangrove: H. H. M. BowMAN. The progress of revegetation in the Katmai district: ROBERT F. GRIGGS. Observations on the edge of the forest in the Katmai district: ROBERT F. GRIGGS. The influence of environment on sexual expression in the hemp: J. H. SCHAFFNER. A double mutant of the hemp: J. H. SCHAFFNER. Translocation and storage of carbohydrates in apple fruit spurs and two-year-old seedlings: SWARNA KUMER MITRA, Jaron and Fanport members in Ohio: WILBER STICT. resumite human embryo: C. L. TURNER. Burn of catalase to activity: R. J. SEYMOUR. Sum Features of industrial fatigue: E. R. HAY Fimic encephalitis: ERNEST SCOTT. 1urement of blood pressure by resistance of arbon discs: E. P. DURRANT. Satire characteristics of first grade children: MARY E. MILLER. study of the lowest five per cent. of college stuBrats as determined by the army alpha examinaD: HELEN MARSHALL. study of the highest five per cent. of college students as determined by the army alpha examinatoms: EARL R. GABLER. Experimentation in the psychology of music: ESTHER L. GATEWOOD. Mental and educational tests of the deaf: JEANNETTE REAMER. Syphilis and delinquency: FLORENCE MATEER. DEMONSTRATIONS Black tumor of the catfish: R. C. Osburn, born. Caddis cases covered with sponges: F. H. Krecker. Wax models of 8 mm. and 12 mm. chondrocrania of Syngnathus: J. E. Kindred. Models of pre-somite (Mateer) human embryo: C. L. Turner. Specimens from the Valley of Ten Thousand Smokes: Robert F. Griggs. Wireless telephone: R. A. Brown. DELAWARE, OHIO EDWARD L. RICE, Secretary SCIENCE A Weekly Journal devoted to the Advancement of Science, publishing the official notices and proceedings of the American Association for the Advancement of Science Published every Friday by THE SCIENCE PRESS LANCASTER, PA. GARRISON, N. Y. NEW YORK, N. Y. Entered in the post-office at Lancaster, Pa., as second class matter |