CONCERTED BEHAVIOR OF TERRESTRIAL

MOLLUSKS

ON August 29, 1915, the writer collected 125 specimens of Cochlicopa lubrica (lot 146a) from the outer surface of the door and frame of the "dark room" at the Iowa Lakeside Laboratory, on Lake Okoboji. This small frame building is more than half imbedded in the hillside about 15 feet above the level of the lake. The roof is covered with humus dirt and vegetation. A short passageway walled with heavy boards leads to the doorway.

Throughout the preceding night there had been a constant, cold rain. On the morning of the 29th there was a cold, drying wind. On the afternoon of this day I chanced to notice a specimen of Cochlicopa on the door-frame; closer examination then revealed a good many, and I spent an hour or more in gathering them. Those attached to the walls were at all heights, with the apex directly downwards, which latter fact, I presume, indicates that their movement had been upwards. None of the specimens were moving at the time, but all were retracted and fastened by a secretion to the substrate. Doubtless this condition is explained by the fact that the wind had made the planks so dry that locomotion was difficult or impossible. Ten or fifteen specimens were picked up from the ground close to the wall, but were inactive and lay as they had fallen. A few, also, were found in cobwebs, by which they had been caught as they fell from the vertical walls. While a few specimens were found on the south wall, most were on the north wall (which faced the south) and the northeast corner of the building (which faced east to north). Besides the Cochlicopa, a considerable number of specimens of Vallonia gracilicosta were found; and also about fifteen specimens of Bifidaria armifera. However, the two latter species did not exhibit any uniformity in orientation, so far as noticed, at least.

Concerning the Cochlicopa, the writer was puzzled to account, not only for their presence in rather large numbers, but for the singular uniformity of their behavior. The snails on the vertical walls were at all heights from the ground, and all exhibited precisely the same

orientation, viz., the apex of the shell pointed downward. They evidently had come from the ground below. But why should they be moving upward? Under conditions of drouth and cold one would expect these forms to exhibit a positively geotropic response. Close to the water's edge among the rocks and fallen leaves the writer had been accustomed to find this species rather common; but never so many in a given area as occurred on this occasion. None had ever been found on this slope so far up, before.

It seemed to the writer that so many of these snails being found together, and with similar orientation, was a fact inviting explanation, which, however, he is unable to furnish. This case differs from the synchronic behavior recently described in SCIENCE by several authors, in that it lacks the element of rhythm. In the movement of the group of harvestmen, as described by Newman, and the simultaneous movement of the fall web-worn, described by Peairs, there is a rhythmic group movement which may be distinguished from concert of action. And while I am unable to explain the behavior of these snails, I am inclined to look upon it as a sort of concerted action.

MORNINGSIDE COLLEGE, SIOUX CITY, Ia.

T. C. STEPHENS

A COUNTRY WITHOUT A NAME

TO THE EDITOR OF SCIENCE: I am glad to see that some one has at last had the insight and courage to note and call attention to the fact that our nation has no name. "The United States" is no name at all, and merely because we call the United States of Mexico "Mexico," and the United States of Brazil "Brazil," is no justification for calling the United States of America "America." Our brothers to our north call us 66 the States," which is about as meaningless as anything can be, but it is our own fault that we are so called. Some years ago there was a popular musical comedy containing a song entitled "My own United States," but it could arouse no thrill with such a handicap. Indeed we do need a national name more than a national flower,

TO THE EDITOR OF SCIENCE: The name "America" inspires millions of individuals and the logical necessity for a name which is more specific, as pointed out by one of your correspondents in SCIENCE of July 5, will gain little acknowledgment and no popularity. Nevertheless the necessity remains and should be dealt with. The custom and sentiment of the masses is the deciding factor and any change can come only by a gradual transformation. If the term America, like Europe, Africa and Asia applies to a continent, as it does, then American implies Canadian, Brazilian and Patagonian just as well. We have in our case the modifying factor of "United States," which, as the correspondent puts it: "is lacking an adjective." To supply this adjective another name is needed. Why not hit two marks in one stroke by printing upon our postage stamps: USONA? Perhaps this name might gain popularity and would permit an adjective "Usonian." At the same time the most numerous representatives of the nation would sail under a more specific label: U. S. o. N. A. instead of U. S. POSTAGE. Incidentally I wonder how long the inaccurate use of U. S. A. will survive. It has often been pointed out that U. S. A. is the official abbreviation for "United States Army" and U. S. N. for the navy, while U. S. means the United States and U. S. N. A. the United States of North America. Perhaps an experiment with postage stamps, as suggested above, may educate the people to use Usona, or the correct U. S.

BERKELEY, CALIF.

INGO W. D. HACKH

SCIENTIFIC BOOKS

City Milk Supply. By HORATIO NEWTON PARKER. New York, McGraw-Hill Book Company, Inc. Pp. 486.

The author's purpose is plainly set forth in the brief preface, namely to give much-needed information on the broad subject of milk production, transportation and control of purity. This purpose he has admirably accomplished. The book seems complete in itself. The subject matter is divided into seven chapters, as follows: I. Milk; II., Diseases Communicable in Milk; III., Dairy Cattle and the Dairy Farm; IV., Sanitary Milk Production; V., Transportation of Milk; VI., The Milk Contractor, and VII., Control of the Public Milk Supply.

Printed in somewhat compact form, in good bold type and on good paper, the different topics are presented clearly, and in many parts with the first-hand information and understanding of the various difficult problems which only one who has spent many years of study in this field is able to give.

In the chapter on diseases communicable in milk the treatment of tuberculosis is particularly instructive. The tuberculin test, and the present-day controversy regarding its value and enforced application are discussed at some length and without bias. Septic sore throat likewise comes in for a good share of the writer's attention.

A comprehensive history of the score card system of rating dairies, and a full discussion of its merits and of its serious limitations will be found to be interesting and illuminating. The importance which the author attaches to the bacteriological examination of milk is most gratifying to those who have long lent their support to its complete adoption as a method of controlling sanitary milk production. A good account is given also of the origin and pernicious influence of the so-called "slop dairy," and of the long struggle that has been waged for improved feeding and housing conditions in the dairy barn.

The author has been particularly successful in his treatment of the material in the chapter on the milk contractor. The peculiar

relations of the contractor to both the producer and consumer are well portrayed, and the many and almost insurmountable problems of bringing milk to the doors of the consumers in as pure a state, and as quickly as possible, without prohibitive cost, are clearly presented and discussed from every possible angle. The pages in the last chapter on municipal and state control of milk production and distribution, with types of ordinances as examples, should be of much interest to health officers and milk inspectors. The practical applica

jected intraperitoneally rats with suspensions of corpus luteum preparations.1 In all but one animal the substance prepared by Armour & Company was used.

While Corner and Hurni find that such injections may cause peritoneal adhesions and peritonitis, they failed to inhibit ovulation. So far the experiments of these authors are essentially in agreement with the results not mentioned by Corner and Hurni which I previously obtained in guinea-pigs.2 I stated:

While in some injected guinea-pigs ovulation was

It is unfortunate that grammatical errors should have been allowed to creep into the book here and there, as for example the following: “Enough data has been collected" (page 180), and "the relations between the farmer and city milkman is delicate"; and in the use of scientific names, as for instance in streptococci, staphylococci and bacteria were found." A very common error in punctuation is the absence of the comma between the principal parts of a compound sentence, especially where the conjunctive "but" is used. These are, however, but minor defects which will undoubtedly be eliminated from future editions.

The author does not claim originality, but as he states, has drawn from a wide field of experience of others, experts in their own domain, who have been given full credit, and to whose work references are given at the end of the individual chapters. Throughout the book original tables and illustrations materially add to its value. LEO F. RETTGER

SHEFFIELD SCIENTIFIC SCHOOL,
YALE UNIVERSITY

SPECIAL ARTICLES

CORPUS LUTEUM AND THE PERIODICITY IN THE SEXUAL CYCLE

In a recent paper G. W. Corner and F. H. Hurni report on experiments in which they in

expected term despite the fact that these animals had repeatedly received large doses of lutein. We may therefore conclude that injections of lutein extract can not wholly take the place of the living corpus luteum. Whether or not they can do so partially in mammals, I am not prepared to say on the evidence at hand.

Some details as to doses used in these ex

periments are found in a paper in which in conjunction with Dr. Cora Hesselberg I reported on the effect of such injections on the cycle of the mammary gland in the guineapig.3

Our experiments on the effect of injections of corpus luteum substance had been suggested through positive results which R. Pearl and Surface had previously published concerning the retarding effect of such injections on the ovulation in birds.4

We emphasized the negative character of our results, because a slight delay in ovulation can be induced in the guinea-pig through various experimental interferences, and especially did we find that undernourishment prevented the normal maturation of follicles.

The experiments in which ovulation oc

1 George W. Corner and Felix H. Hurni, American Journal of Physiology, 1918, XLVI., 483. 2 Leo Loeb, "Surgery, Gynecology and Obstetrics," 1917, XXV., 300.

3 Leo Loeb and Cora Hesselberg, Journal Exper. Medicine, 1917, XXV., p. 305.

4 Raymond Pearl and F. M. Surface, Journal Biol. Chem., 1914, XIX., p. 263.

5 Leo Loeb, Biological Bulletin, 1917, XXXII.,

p. 91.

curred at the normal term, notwithstanding the injections, seemed to us therefore of greater significance. Corner and Hurni, however, go further in their conclusions and state: "Thus it would seem that Loeb's experiments do not prove an acceleration of ovulation following the removal of the corpora lutea."

This conclusion rests (1) on the lack of effect of the injection of dried corpus luteum substance in inhibiting ovulation. (2) On the alleged proof given by Stockard and Papanicolaou that I assumed the normal sexual cycle in the guinea-pig to be longer than they found it to be by a method which they believed to be superior to the one which I used.

Inasmuch as, to my knowledge, my investigations provide the essential experimental basis for the conclusion that the corpus luteum has the stated function, and that the denial of the correctness of my conclusion would invalidate the significance of the corpus luteum as an important factor in the mechanism regulating the sexual cycle, I believe it advisable to inquire whether or not the statement made by Corner and Hurni is warranted by facts.

Without going into a detailed restatement of the results which I have published in a series of preceding papers, I may give a brief summary of some of the essential results obtained. In a first series of investigations I determined the duration of the sexual cycle in guinea-pigs in which in most cases the uterus had been subjected to certain experimental interferences in the early period of the sexual cycle. It was found that while in these cases the second ovulation may occur as early as 16-18 days after the first ovulation, it occurred quite commonly somewhere between the twentieth and thirtieth day after ovulation; this was found to be so, especially in cases in which through incisions made into the uterus deciduomata had been produced experimentally. In a series of guinea-pigs in which the uterus had been treated in a way similar to the control series, but in which, in addition, at an

• Leo Loeb, Deutsch. mediz. Wochen., 1911, No. 1. Zentralblatt f. Physiol., 1910, XXIV., No. 6; 1911, XXV., No. 9.

Α

early stage of the sexual cycle the corpora lutea had been completely extirpated with a knife, ovulation occurred in the large majority of cases between the twelfth and sixteenth day after the first ovulation. period of approximately 9 to 13 days following an ovulation is required for the new formation of mature follicles in the guineapig, each ovulation in the guinea-pig being accompanied by an atresia of all but the smallest follicles. While this series, as such, proved the significance of the corpus luteum for the duration of the sexual cycle, the correctness of our interpretation was made certain by our further finding that while in the normal course of pregnancy ovulation does not occur in the guinea-pig, after a preceding extirpation of the corpora lutea about 6-7 days following copulation the pregnancy may proceed, but an early ovulation occurs, notwithstanding the presence of pregnancy just as it does after extirpation of the corpora lutea in the cycle unaccompanied by pregnancy. In this case the difference in the time of ovulation is so great as the result of the extirpation of the corpora lutea that an error of interpretation can be exIcluded with certainty.

Extirpation of the corpora lutea did not exert this effect on the sexual cycle in a purely mechanical way; excision of control pieces of ovarian tissue did not have the typical effect; neither did such cases respond in which the extirpation of the corpora lutea was incomplete. Complete extirpation of corpora lutea on the other hand exerted its effect on both ovaries, even in cases in which one of the two ovaries had been free from corpora lutea at the time of extirpation. It was probable that this inhibiting effect of the corpus luteum was due to the secretion of a substance on the part of the corpus luteum.

In further experiments I showed that the presence of the corpus luteum did not inhibit the maturation of follicles, but merely the rupture of mature follicles.

In my first publication I called attention to the possibility that the experimental interfer

7 Leo Loeb, Journal of Morphology, 1911, XXII., p. 37. Virchow's Archiv, 1911, CCVI., 278.

ence with the uterus which was practised in these cases might somewhat modify the duration of the sexual cycle, but that if such a modification did exist, it applied equally to experiments in which the corpora lutea had been extirpated and to control cases. Therefore our conclusions concerning the inhibiting function of the corpus luteum was not affected by such an interference. However, we had intended to continue our investigation in this direction and in later determinations we found, in guinea-pigs in which the uterus had not previously been interferred with, the length of the sexual period to vary between 15 and 18 or 19 days. In two cases we observed the new ovulation as early as 13 to 14 days after the preceding ovulation. A certain latitude exists therefore in the periodicity of the normal sexual cycle.

Again we could confirm our previous results: Excision of the corpora lutea carried out within the first week after copulation brings about a new ovulation between the tenth and fifteenth day after copulation in the majority of such cases, and we were able to observe it as early as 8 and 9 days after copulation.

As in our previous experiments pregnancy did not prevent the early ovulation after a complete extirpation of the corpora lutea. It is only the persistence of the corpora lutea of pregnancy which prevents ovulation.

While in our previous investigations we had studied mainly the cyclic changes in the ovaries and only incidentally referred to cyclic changes, in the uterus, in the last-named paper we extended our studies to the cyclic changes in the uterus and to the correlation of the cyclic changes in the uterus and ovaries. In our determination of the sexual cycle we made use of the following criteria:

1. Whenever feasible the period of heat was observed; the behavior of the animal as well as the condition of vulva and vagina serving as indicators, which in the hands of an experienced breeder gave reliable results as the subsequent macroscopic and microscopic examination of uterus and ovaries proved in each case.

8 Leo Loeb, Biological Bulletin, 1914, XXVII.,

p. 1.

In other animals the observed copulation indicated the approximate time of ovulation. We followed the cyclic changes in uterus and ovaries from day to day and could thus establish a definite and orderly sequence of events. By correlating the condition of the corpora lutea, follicles and uterine mucosa, it was possible to determine the stage of the sexual cycle of the observed guinea-pigs with a precision which was entirely adequate for our purposes. Thus to mention only one instance it was possible by microscopic examination of the uterus alone without examination of the ovaries to determine whether in an animal at an early stage of the sexual cycle ovulation had or had not taken place.

Subsequent to our last mentioned investigations, Stockard and Papanicolaou published a study of the sexual cycle in the uterus of the guinea-pig, in which they used the naked eye observations of vaginal changes as a criterion of the stage of the sexual cycle. These investigators confirmed in all essential points our previous results, though they do not mention our principal paper in which we gave a detailed description of the uterine cyclic changes in the guinea-pig. This omission, Dr. Stockard informed me later, was due to his failure to read my paper.

The difference in the duration of the sexual cycle in our first and second series of experiments led to a further elucidation of the factors on which the mechanism of the sexual cycle depends. We found that the presence of experimentally produced deciduomata without accompanying pregnancy prolongs the duration of the sexual cycle, but only in cases in which the corpora lutea are present. After extirpation of the corpora lutea an accelerated ovulation takes place notwithstanding the presence of living deciduomata; the deciduomata act, therefore, in a way similar to pregnancy. We found furthermore that after degeneration of the deciduomata ovulation oc