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sions in this particular book. Some recent books on astrophysics are quite as badly at fault in this matter. One, for example, makes no mention of Huggins, Keeler, Langley or Vogel!

Again, every astronomer is aware that the total number of stars in our stellar system is an unknown quantity, though we arrive at estimates of this number by extrapolation. Thus,1 in what is probably the most careful and reliable investigation of the number of the stars that has so far been made, it is said, "the assumption that these formulae [i.e., the formulae which represent the number to the 21st photographic magnitude] also apply to the luminous stars beyond observational reach leads to 3 × 1010 [30 billion] as the total number of stars in the galactic system" (italics mine). He knows that measures of stellar diameter are possible at present only by means of the interferometer and that these diameters when given in linear units (miles or kilometers) depend in part upon the adopted distance (parallax), which may be uncertain by 25 per cent. or more of its total value. Antares, for example (which is the largest star of measured diameter, unless, perhaps, Mira Ceti slightly exceeds it), has a diameter of 280,000,000 miles on the basis of one assumed parallax, and of 430,000,000 on the basis of another, the former being probably (but not certainly) the more reliable.

But in a recent popular article, printed in a journal of high standing and later reissued as a reprint by the observatory with which its author is connected, we find the categorical statements: "Our Milky Way system contains about fifty billion stars," and, a star is "a sphere of glowing gas varying in size from a globe not much larger than the earth to one a thousand times larger (italics mine) than the sun in diameter," i.e., more than 860 million miles, or double, possibly treble, the value of the star of largest measured diameter.

The author also remarks blithely that "fifty billion years is but a short interval in the life of the average star," which may (or may not) be true, but is certainly not a demonstrated fact. Furthermore, he lets the reader infer, as a friend pointed out to me, that the Magellanic Clouds have recently moved so far north that their radial velocities can be and have been measured from Mount Wilson or Flagstaff!

The question is this: Is it quite fair to the intelligent public to give the impression, which the average reader will certainly gain from this article, that these figures and dimensions are matters of knowledge and on the same footing as our knowledge of the distance

1"'Mean Distribution of Stars according to Apparent Magnitude and Galactic Latitude," by F. H. Seares, P. J. van Rhijn, Mary C. Joyner and Myrtle L. Richmond. Contrib. Mt. Wilson Obs., No. 301, 1925.

to the sun or of its diameter? Does not the writer of such an article owe it to his reader to make it clear that some of his results rest upon theories, assumptions and extrapolations, all of which, though they may now seem to us to be well-founded, may be subject to revision-possibly even to rejection-in the light of further investigation?

Finally, to revert to my opening paragraph: while every scientific investigator is concerned primarily with the advancement of knowledge, and not with his own fame, is it not his due to be given recognition for his work in books that record for the student the chief steps in the development of his science? R. G. AITKEN

ON MANSON'S EYE WORM IN POULTRY IN certain sections of Florida, especially the seacoast areas, quite severe outbreaks of Manson's eye worm (Oxyspirura mansoni) in poultry occur each year, occurring most frequently during the rainy season of the summer months. Due to its economic importance, and also since its life history was unknown, a detail study of the parasite was begun in November, 1925, by Dr. D. A. Sanders, of the veterinary department, Florida Agricultural Experiment Station.

The first experiments conducted were simply exposure tests to determine if the parasite would pass from infected to non-infected birds kept under continuous exposure. It was impossible to transmit the parasite by simple exposure of non-infected to infected birds.

Experiments were conducted in an effort to produce infection by placing eggs containing embryos of the parasite into the eyes of non-infected birds. It was impossible to produce infection in this manner.

It was also found impossible to produce infection by placing newly-hatched larvae into the eye of noñinfected birds.

From the above-mentioned experiments, it was quite apparent that an intermediate host was necessary in the development of the life cycle of Manson's eye worm. Search for the intermediate host was begun, and this search included examinations of many of the insects most commonly found around the premises of the poultry flock. After examining many insects, finally specimens of Pycnoscelus (Leucophaea) surinamensis Linn., a species of cockroach, were examined and encysted larvae of the eye worm were found in the body cavities of some of these roaches. Larvae were taken from the infected roach, and when placed into the eyes of birds, these larvae remained therein and produced infection. Larvae were taken from the body of a roach and placed into the mouth cavity of non-infected birds with the result that

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shortly afterwards, the birds showed infection of Manson's eye worms. Whole roaches were fed to noninfected birds with the results that within twenty to thirty minutes after the birds had eaten the roaches containing larvae, the parasites had reached the eyes of these birds.

The results obtained by Sanders in Florida confirm the work of J. W. Fielding as reported in The Australian Journal of Experimental Biology and Medical Science Vol. III (1926) that Pycnoscelus (Leucophaea) surinamensis is the intermediate host for Manson's eye worm of poultry. However, the work of Sanders in finding this intermediate host was done independent of Fielding's work.

The mature parasites are located in the tear sinus just beneath the third eyelid or nictitating membrane. In some cases, birds harbor only one or two parasites, while in a severe infection as many as fifty or more parasites may be present in the eyes. The mature parasite is 14-18 mm. in length and thread-like in diameter.

T It is possible to infect many different kinds of wild birds by feeding them infected roaches.

AGRICULTURAL EXPERIMENT STATION, UNIVERSITY OF FLORIDA

A. L. SHEALY

RE NOMINA CONSERVANDA EVEN after being so professorially lectured in SCIENCE1 in an article which could more appropriately have appeared in the same medium as did the paper it attacks, the writer wishes to reply only to the extent of clearing up possible misapprehensions

in the minds of readers.

By implication the writer is classed with those having the "mihi itch" in an objectionable form. He would state therefore that his object from his very first paper on entomological taxonomy has been to do essentially revisional work that would have a maximum of teaching value to younger entomologists and be a real aid to identification of species in the hands of more advanced students. To date he has been sole or joint author of fifty-two articles dealing with the classification of insects and thirty-nine of these are revisional in scope or at least include keys. The piling up of mere descriptions of new species has never been his object; but on the contrary is an activity he heartily condemns. At the same time he believes that personal interest in achievement is no more lacking in taxonomic work than in other fields of human endeavor, and that this is only as it should be, altruistic platitudes to the contrary notwithstanding.

1 Bradley, J. Chester, 66, 100-103, July 29, 1927.

Professor Bradley insists on the separability of taxonomy and nomenclature, but passes over the writer's suggestion that a code of vernacular or other names could be used by general biologists that would have no necessary connection with technical taxonomy.

Bradley's reference to general zoologists, morphologists, etc., riding rough shod over taxonomists is certainly well put, for just that is what has been attempted in the making of nomina conservanda. Taxonomists deal constantly with morphology and use morphological terms almost as much as the morphologists themselves, yet they have not attempted to dictate standardization of anatomical terms, new ones of which are constantly being introduced. Taxonomic nomenclature is no more the language of science than is anatomic nomenclature and is no more subject to dictatorial rule.

Bradley ends on a note of not becoming a slave to rules, which he may be sure finds an echo in the breasts of men so individual and independent as taxonomists usually are. They desire to be the slaves neither of rules nor of rulers (i.e., of Committees and Congresses).

W. L. MCATEE

EARTHWORMS AND SPECTRAL COLORS THE article by W. R. Walton on "Earthworms and Light" in SCIENCE for August 5, 1927, recalled to me some research I did in this line some years ago but did not publish.

For the experiment I used a box about two and a half feet long, two feet wide and eighteen inches high. This I thoroughly blackened inside. For light I used gas with a mantel and a reflector. The light was passed through a carbon-di-sulphide prism. The light fell on a white paper in the bottom of the box. Into this array of spectral colors I dropped angleworms. As they moved to get away from the light they always went out the red end. They would pull back from the blue as if it hurt them and turn toward the red. This reaction occurred with every worm except one. This worm lay full length in the green and stayed there. I was not able to repeat this last reaction. G. H. BRETNALL

BAKER UNIVERSITY

SCIENTIFIC APPARATUS AND

LABORATORY METHODS

A SIMPLE AUTOMATIC DEHYDRATING APPARATUS FOR MANY SMALL OBJECTS THE accompanying figure represents a very satisfactory apparatus for changing fluids on many small objects. It grew out of the need for saving time in handling ovaries of mice. It is essentially a glass

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tube about 300 millimeters long by 16 millimeters inside diameter supported at an angle of about 30 degrees, fitted with a glass stopcock at the lower end and with a 2-hole rubber stopper at the upper, through which fluids are conducted from the supply bottle. The overflow tube fitted into the rubber stopper serves two purposes. When the large glass tube is being filled from the supply bottle, it allows air to escape; and also prevents overflow when the tube is full and the stopcock closed. A retort stand fills all the needs of a support, if fitted with rings and clamps as shown in the figure. Other means of support are readily devised. The supply bottle is of the aspirator type.

As used by the author, each ovary is put into a short piece of small glass tubing, the ends of which have been smoothed on a small emery wheel. The corresponding number is written in pencil on a small strip of paper and placed with the ovary in the tube, which is then wrapped in a piece of loosely woven cotton cloth, fastened at the side by either thread or fine copper wire, leaving only one layer of cloth over each end of the tube. Many of these small tubes, each with its numbered ovary, are placed in the large glass tube which is filled with the appropriate fluid, clamped in place, connected to the supply bottle as shown, and the desired fluid allowed to flow in. For

example, if the next step is to pass from 30 per cent. to 95 per cent. alcohol, this latter fluid is placed in the supply bottle, and the glass stopcock adjusted to a very slow rate of dropping, perhaps one drop per second. The 95 per cent. alcohol passes very slowly into the tube at the upper end, is diluted and the mixture gradually works its way downward. Ultimately the tissues are in 95 per cent. alcohol. By placing a small loose wad of absorbent cotton at the two places indicated in the figure (C and cotton), it was seen by admitting colored alcohol from the supply bottle into water or a low grade of alcohol in the glass tube, that the front of the new mixture moved evenly, thus proving that all the objects in the glass tube would be affected serially from top downward.

It is wise not to put tissues between the upper wad of cotton (C) and the 2-hole rubber stopper, as the amount of fluid contained in this space allows mixing of the two fluids, which prevents too sudden a change on the upper pieces of tissues. The large glass tube holds about fifty of our small glass containers, which measure about 15 mm. long by 5 mm. inside diameter. These are easily cut in the laboratory. The large glass tube and the small containers may be varied in size according to the needs of the user; but it is likely that if the large tube is much greater in diameter the flow of the fluid might be difficult to control evenly. Several tubes may be filled and joined end to end for simultaneous treatment.

The inflow may be checked at any time by closing the glass stopcock. Tissues may remain immersed any length of time in a particular fluid without loss of fluid by evaporation. They may be fixed, washed, stained, dehydrated and cleared without further handling. So far as the author can see, this device is as reliable as an air current or a mechanical agitator. The user will realize the necessity of a very slow movement of fluids. The dropping may be regulated to any rate desired, from less than a drop per second to as many as may seem best. The clearing fluid should probably be added more slowly than the alcohols, and be started in a mixture with 95 per cent. or 100 per cent. alcohol. In placing the small containers in the large glass tube, one should avoid closing either end by contact with another surface. Small animals and some hard tissues may be kept separate by mosquito netting or cloth sacks only.

If the apparatus is used for staining it is well to make new paper labels before infiltrating the tissues with paraffin, as pencil marks are likely to be dimmed if the stain remains in the paper, and consequently difficult to read when covered with paraffin. Paper labels may be avoided by numbering the small glass tubes and keeping complete corresponding records.

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SPECIAL ARTICLES

SURVIVAL OF ABILITY HAVING found from two different sources unmistakable confirmation of an earlier research of mine showing that mental evolution is going on to-day through a process of natural selection, I would like to present briefly the results, as the full publication may be for some time delayed.

It is often stated that there are now no forces at work to lead towards increase of brain power, because the primitive struggle for existence has ceased to be operative under present conditions of civilization, in which the weak and incompetent are bolstered up and the poor and shiftless are allowed to have many offspring.

It appears, however, that society is being divided into two classes, a small percentage of "aristocrats" and a large percentage of proletariat.1 Within the so-called aristocracy there is taking place a genuine process of survival of the fittest in which the more ambitious, successful and intellectually eminent are having a larger number of children than their friends and relatives who are less well endowed.

In studying the royal families of Europe I found this to be the case (see "Heredity in Royalty," 1906). Now I have found it to be the same among Harvard graduates and also in the British peerage.

Mr. A. E. Wiggam, writing in the World's Work for November, 1926, page 32, makes comment upon the figures for Harvard graduates, which I sent him as confirmation of a belief I have held for twenty years that by-and-large all good human qualities are correlated and therefore mental evolution must continue. Also such facts give an added justification for eugenics and a brighter outlook for the future of mankind. This point of view is contrary to the attitude of Conklin, Pearl and Castle if I interpret their writings correctly, but is accepted by Thorndike; and I think by Terman judging from this same article by Wiggam.

This announcement of mine regarding Harvard graduates has apparently stimulated a number of people to look up the records and see if it be true. This I gather through correspondence. John C. Phillips writes me that he is finding confirmation.

1 See F. A. Woods, "Social Conification," in Proceedings of Second Eugenics Congress, 1921. Published in "Eugenics, Genetics and the Family," 2 vols., Baltimore, Md.

No figures have as yet been published. Those which I possess are for only four graduated classes, '90, '92, '94 and '98. I had hoped to include '96 for the sake of symmetry but the figures as they stand are sufficient to make the conclusion almost certain that judged by the oft-used standard of success, "Who's Who in America," the graduates who are parents of three or more children are a little more likely to be in "Who's Who" than those with less and much more likely than the bachelors. All figures are taken from the class books made up on the twenty-fifth anniversary after graduation, which books have at least the appearance of approximately sufficient care, accuracy and completeness.

PERCENTAGES OF HARVARD GRADUATES IN "WHO'S WHO IN AMERICA, '' 1924-25

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It can be seen from the figures that no one would suspect from the data regarding any single class, that any such truth lay buried. Take the Class of '90, for instance, which was the first investigated. Here the unmarried have actually a higher percentage of inclusion in "Who's Who in America" than those with four or more children. The grand average, however, smooths the curve out, giving the two highest percentages at the right, 18.92 and 18.09, with the lowest at the left, 9.71, for the bachelors. The remaining figures are satisfactory though the rise is not perfectly uniform. If we add the percentage of the bachelors to the married without children, and divide by two we get 13.08 for the childless compared with 16. +, 16 +, 18+, 18+ for the other four groups. The total number of individual cases studied is well over 1,000, which is the number usually necessary in correlation investigations.

This confirmation of the results from the royal families led me to believe that the same truth would undoubtedly be found in the records of the British peerage, namely, that the more notable or able, are (within any one homogeneous social class), the ones who have the largest number of living children. The well-known "Burke's Peerage" is an exceedingly complete and accurate book. I have divided all the peers (Edition of 1921) into two groups: first those whose male lines are traceable as early as 1450, and second,

those whose male lines are not traceable to such an early date. This bears on the average some relationship to the date of elevation to the peerage, but that is another matter.

These in the first group are the peers who belong to the very old families, so-called. They constitute about half of all the peers. Their family names are well known to everyone conversant with English history.

As regards their achievements, which must be in a considerable degree due to a mixture of ability, vitality and ambition, they have all been placed in two groups. First, a comparatively small group who have done nothing or next to nothing in the way of rendering public service and, second, a majority group whose public services appear to have been both genuine and continuous. Naturally there are border-line cases difficult to place, but these are not very numerous and I have been careful to place the doubtful cases in such a way that they would count against rather than in favor of my theory. Only those over 34 years of age have been included.

All who have been elected members of parliament or risen in the navy to the rank of commander or colonel in the army (not honorary colonel), also those who served in the great war, have been included in the "service" group as well as the few business and professional men. Both "Burke" and "Who's Who" have been consulted for each case. Generally speaking if there is anything in their biographies that can be called "service" they have been included in this group.

In spite of this liberality of inclusion in the "service" group there are about 68 among the peers of the newer families whose achievements appear to be either nothing at all, or very inconsiderable. These have 138 living children, which gives an average of

2.03.

There are about 274 peers of the newer families who come within the "service" group. These have 640 living children or an average of 2.33. An even greater rise is to be found in favor of the greater fecundity of the peers who have rendered "service" when we summarize the facts concerning the older families. Here about 70 peers with little or no public service to their credit have 131 living offspring or an average of 1.87, while 210 "service" peers have 610 living children. The average for living children here rises to the surprising height of 2.90.

The English peers evidently want children and they have them. The best among them apparently want them the most, so that in spite of the large number of sons killed in the war, this special caste of humanity is more than holding its own.

Dr. J. McKeen Cattell and others have shown that parenthood to-day is largely a voluntary matter, at least among the more intelligent classes. The desire for children is doubtless in part an instinct and as far as it is an instinct should be subject to hereditary transmission. It is in all likelihood correlated with such virtues as domesticity and stability. It appears from these figures to be also correlated directly with intelligence and ambition. When we reach the type of ability generally called genius there is again a falling off in the number of offspring, but it is a matter of satisfaction to know that within the different groups of humanity there is by-and-large a survival of ability.

The average for total offspring for all college graduates is lower than it ought to be to keep up the type. For all Harvard graduates it averages below two. Some may say, "What is the use of survival of ability when if this goes on long enough there will not be any ability left to survive." The answer to this is a long one and can only be indicated here. Voluntary parenthood is a recent phenomenon. The average for all graduates, circa 1.5, rises for the more successful to circa 1.6. As nowadays only those who want children have them, the children should themselves inherit this temperament. This is a new condition which did not exist until recently. From now on this inheritance of the parental instinct should in a few generations restore the number to a little over two, which is necessary for a continuance of the breed.

It is true that the people of the slums are having undesirably large families, but this class is now almost entirely separated as far as intermarriage is concerned from the upper classes-more so in England than in the United States, but increasingly so on both sides of the Atlantic. It is probable that an intensive study of families within the slums where brother could be compared with brother and sister with sister would show the same result, namely, the better members of the family having the largest number of surviving offspring.

FREDERICK ADAMS WOODS

QUANTITATIVE HYDROLYSIS OF STARCH BY BUFFERED TAKA-DIASTASE THIS work represents an attempt to eliminate the use of acid hydrolysis in determining the starch content of plant material.

The standard method is the "maltose hydrolysis." This consists in treating the alcohol extracted materials with taka-diastase in water solution, filtering off the insoluble residue, and heating the filtrate with dilute acid to hydrolyze the dextrin and maltose to

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