detection, were explained by the speaker, and a large array of choice specimens of adulterated goods were shown which furnished strong testimony to the cupidity of some manufacturers of food articles and, in many cases, to their lack of regard for human health.

The

The second paper of the evening, by Dr. C. A. Fuller, was on the subject, 'The Dissemination of Typhoid Fever by Oysters.' Outbreaks of this disease have occasionally been traced to infected oysters. Bacteriological examinations of these shell-fish usually demonstrate the presence of bacterium coli. survey of 3,000 acres of oyster ground in Rhode Island waters showed that both water and oysters from sections within six miles of the outlet of the capital city sewer contained sewage bacteria, while samples taken at a greater distance from the source of contamination were not infected; similar conditions were observed to prevail in a number of the oyster beds on the east coast of the United States. F. W. WOLL, Secretary.

THE second yearly meeting of teachers and students of experimental psychology was held. in the Clark University laboratory, at the invitation of Professor E. C. Sanford, on Friday and Saturday, March 31 and April 1. At the first session, on Friday afternoon, papers were read by Mr. L. M. Terman, on 'Tests of Bright and Dull Boys'; by Mr. A. L. Gesell, on 'Handwriting and Scholarship'; and by Mr. W. F. Book, on the 'Learning of Typewriting. The visitors then inspected the laboratory, under the guidance of Professor Sanford, who demonstrated, among other instruments, two devices for the determination of the temporal limen of disparate sense impressions, a rotating-prism color mixer, and an apparatus for investigating the sensible discrimination of purple. Professor A. H. Pierce, of Smith College, next described three researches now in progress in his laboratory; and a paper by Professor Max Meyer ('Auditory Sensations in an Elementary Laboratory Course') was read by Mr. H. C. Stevens,

of Cornell University. A discussion followed, in which Professors Pierce, Sanford and Titchener took part. In the evening the visiting psychologists were entertained at dinner by Professor Sanford.

The session of Saturday morning was opened by President Hall, with a paper on 'Some Tendencies and Dangers of Experimental Psychology.' The paper was discussed by Dr. Hylan and Professor Titchener. Adjournment was then made to the physical laboratory, where Professor A. G. Webster demonstrated his apparatus for the measurement of the objective intensity of sound. The last hour of the morning was spent in further inspection of the psychological laboratory, after which the guests enjoyed the opportunity of meeting the Clark University students at a luncheon given by President Hall.

At the afternoon session Professor Bentley, of Cornell University, read a paper on the 'Analysis of Tones,' and afterwards demonstrated his method and certain of his results. The meeting was fittingly concluded by an inspection of the new library building, arranged by Mr. L. N. Wilson. All psychologists know the treasures of the Clark University library, and the willing courtesy of their custodian; and all present on this occasion were delighted with the disposition and conveniences of the library.

It was decided to accept Professor Judd's invitation to hold the meeting of 1906 in the Yale University laboratory.

in plants. All other cells of the animal constitute a generation comparable with the sporophytic generation in plants, the fertilized egg being the first cell of this series."

In the diagrams employed in the exposition of his theory he indicates that the animal egg by itself and each spermatozoid is comparable to a plant gametophyte. His statements are not consistent, not in accordance with the facts or even with his figures, and it appears that just where he wishes to draw the homology is not quite clear in his own mind.

Our knowledge of animal phylogeny affords no evidence that the gametes, with their reduced number of chromosomes, are vestigial individuals which at one time in their history lived independent of or apart from the animal body. They do not constitute and there is no evidence that they ever have constituted, a generation in the life-history of any animal organism. If amphimixis occurs in the lifehistory of an organism, a reducing division must also occur. The mechanism of reduction seems, in general, to be bound up in two successive mitoses. That the cytological processes of reduction in plants and animals closely approximate a common plan does, by no means, justify the conclusion that the products are of the same morphological value in the life-cycles of each.

Chamberlain says: "To me the comparison seems so obvious that I can explain the previous absence of a theory of alternation of generations in animals only by the fact that the gamete-bearing generation is extremely reduced and is not approached by any gradual series as in plants. * * *I do not claim any acquaintance with zoological literature further than a reading of the latest edition of Wilson's The Cell in Development and Inheritance.' Were there any theories as to alternation of generations in animals, doubtless they would have been thoroughly discussed in that book."

That zoologists recognize an alternation of generations in the Hydrozoa and Scyphozoa is a common statement of their text-books. That a theory of antithetic alternation of generations in the life-histories of animals has been propounded by certain zoologists, Beard

and Murray,* does not require a knowledge of zoological literature to determine, for it occupies a conspicuous place in a prominent botanical journal as well.

In the course of their discussion Beard and Murray write: "When one seeks in the higher animals for an equivalent of the alternation of generations in plants in the light of recent work on the reducing division of spore-formation, such a morphological mark would only be found in the maturation of the egg and in spermatogenesis. If the process were here a spore-formation, the whole metazoan body, in which it took place, would represent the asexual generation, and any apparent alternation of generations in the life-cycle would be homologous in character, not antithetic."

In speaking of the reduction of chromosomes in the oogenesis of Fucus, Farmer and Williamst call attention to this same analogy in the following sentences: "Thus Fucus, in this respect, approximates more closely to the type of animal oogenesis than to that which obtains in those higher plants in which the details of chromosome reduction have been followed out. Regarded from the standpoint of the number of its chromosomes, the Fucusplant resembles the sporophyte of the higher plants, whilst the gametophyte of the latter, with its reduced number of chromosomes, finds its analogue merely in the maturing sexual cells of Fucus." HAROLD L. LYON.

UNIVERSITY OF MINNESOTA.

SCIENCE AND THE NEWSPAPERS.

TO THE EDITOR OF SCIENCE: Recently three Chicago newspapers (the Record-Herald, the Tribune and the Chronicle) published, without our knowledge or consent, an alleged account of experiments communicated by us to a meeting of physiologists. It is needless to state that this account was quite misleading. We at once sent the enclosed letter to the papers in question. Only one of them (the Record-Herald) pursued the fair and manly course of publishing it. The Tribune did not deign even to acknowledge receipt of our let

* Anat. Anzeiger, 11: 234–255. Ann. of Botany, 9: 441-468.

† Ann. of Botany, 10: 479-487.

ter. The Chronicle refused to print it, but offered to correct any misstatements in its article, an illusory offer in relation to such a tissue of inaccuracies, and one which we had no desire to accept.

We think it right that the scientific professions should know the attitude which the conductors of some newspapers consider themselves justified in adopting towards scientific workers, and we wish to record in your columns, once for all, that protest which they have not permitted us to make in theirs.

G. N. STEWART, C. C. GUTHRIE.

CHICAGO, APRIL 3, 1905. Sir:-In yesterday's issue of your paper there occurs a garbled and misleading account of certain experiments communicated by us to a meeting of physiologists of the central states. We are entirely opposed to the discussion of such matters in the lay press. If any reporter was present at our meeting he certainly was there without invitation or permission. We do not know from what source this remarkable piece of copy reached your office. But we can not think the writer has fully considered how injurious such notices may be to the reputation of scientific investigators; and while we entertain the greatest respect for your paper in its proper sphere, we must beg of you in the future to do us the honor of leaving us and our work alone. We trust that you will give this letter the same publicity as the paragraph to which we object. We remain, yours truly,

(Signed) G. N. STEWART, C. C. GUTHRIE.

A MODEST STUDENT OF ANIMAL PSYCHOLOGY.

IN the preface to 'The Watchers of the Trails' its author, C. G. D. Roberts, writes:

The psychological processes of the animals are so simple, so obvious, in comparison with those of man, their actions flow so directly from their springs of impulse, that it is, as a rule, an easy matter to infer the motives which are at any one moment impelling them. In my desire to avoid alike the melodramatic, the visionary and the sentimental, I have studied to keep well within the limits of safe inference. Where I may have seemed to state too confidently the motives underlying the special action of this or that animal, it will usually be found that the action itself is

very fully presented; and it will, I think, be further found that the motive which I have here assumed affords the most reasonable, if not the only reasonable, explanation of that action.

On page 221 of the same book the author writes:

As the raccoons crept along behind the woodshed they smelt traces of a sickly pungent odour, and knew that other marauders had been on the ground not very long before. This made them bolder in their enterprise, for they knew that such depredations as they might commit would be laid to the account of the skunks, and, therefore not likely to draw down vengeance upon the [raccoon's] den in the sycamore.

MAYNARD M. METCALF. THE WOMAN'S COLLEGE OF BALTIMORE, March 19, 1905.

A NEW FORM OF STEREOSCOPE. TO THE EDITOR OF SCIENCE: I read with interest Professor Whitman's account of his new form of stereoscope in your issue of April 7. I have described the same type of instrument in SCIENCE, Vol. VII., p. 619. I was led to the invention thereof by the instrument called the perspectoscope which mistakenly attempted to get a stereoscopic effect from a single photograph, but in doing so used the convenient device of placing the eyes at right angles to the picture. Using this principle, I made an apparatus with pivoting mirrors which enabled me to throw one of a pair of stereoscopic images into the one eye, and the other into the other, just as Professor Whitman has independently done. I have used this both in combination with weak lenses and without them. I have had such an apparatus in my laboratory for about seven years.

The main advantage of the instrument (its defects are well defined by Professor Whitman) for the psychological student is that it offers a simple means of reversing the perspective without changing the card, throwing the image of the right-hand picture into the right or left eye and correspondingly for the left eye, thus producing a stereoscopic or a pseudoscopic effect; indeed, an intermediate position in which the same view is thrown into each eye is also possible and thus gives the entire range of combinations. The Chicago

Laboratory Supply Company is now making some of these instruments to serve as reversible stereoscopes. In their manufacture the difficulties of projection of the two images to differently situated planes have been encountered, and have been met only by reducing this to a minimum and counting upon the fortunate property of the eyes to ignore or, indeed, to make terms of peace with this discrepancy. I find that this is easy, when an ordinary photograph with no sharp gradations of light and shade is used; but with diagrams the non-correspondence of top and bottom is moderately disturbing. I have not hesitated for purposes of convenience to combine lenses with this reflecting stereoscope; but I shall profit by Professor Whitman's suggestion to see how far the increased proximity of the eyes to the mirrors, which he recommends, will obtain certain of the advantages which I tried to secure by weak lenses. This last variation is a detail of construction in which Professor Whitman's device differs from mine.

THE classification of the bacteria presents peculiar difficulties for several reasons. Morphological distinctions are so slight that physiological characters must necessarily be invoked in order to separate and classify the various organisms, and these physiological characters are often variable. Pathogenicity may be taken as a type of those powers of the organism which are easily and profoundly modified by external conditions. On the other hand, there are numerous characters which appear to be extremely constant. Such minute differences as occur in the resistance of different races to unfavorable conditions often remain unchanged through long periods of cultivation. In using these constant characters for classification we are met by another difficulty. Though constant, the differences are

* Preliminary communication. From the Biological laboratories of the Massachusetts Institute of Technology.

very minute, and in studying a number of organisms a perfect gradation is often found. between the widest extremes. This is exactly what should be expected from organisms which reproduce only by asexual methods since it is the fusion of independent cells which swamps minor differences producing the uniformity of species among higher plants. With asexual reproduction every minute variation which is inheritable must persist unchanged until some other chance variation occurs. Each such variation means a new and different type of bacterium.

The immense number of generations which may succeed each other in a short space of time makes boundary lines as shifting as they would become among the higher plants if a dozen geological epochs were considered all at

once.

Since with unicellular organisms acquired characters may probably be inherited in a higher degree than with other forms, existing races of bacteria will be markedly influenced by the selective effect of environmental conditions, and must bear the impress of their recent history.

There are, therefore, no species among the bacteria in quite the sense in which we ordinarily use the word, as indicating a group of individuals bound together by a number of constant characters and easily identified by mutual fertility. From one point of view each distinct race might be considered a species; but to apply a name for every grade of difference in each varying character would be impracticable; and such names could have no true specific value. The best solution of the difficulty is the establishment of certain types around which the individual organisms may be more or less closely grouped; but it must be clearly recognized that the groups thus formed are defined by relation to the type at their center and are not sharply marked off at their extremities from the other groups adjacent.

It is impossible to make a natural classification of the bacteria, which shall be a true expression of phylogeny by considering a single character at a time,-for example, by dividing a group dichotomously, first according to mor

phology, then according to liquefaction, etc. Larger groups at least should manifestly be indicated by the collocation of several characters, the association of any two of which markedly strengthens their significance. By applying this principle, five fairly well-marked genera of coccaceae may be distinguished. Four of these, Sarcina, Micrococcus, Streptococcus and Ascococcus date back to the early days of bacteriology, although the latter term has fallen into disuse. The mere property of zoöglea formation should not be considered of generic importance, but the few peculiar species which are capable of growing under purely saprophytic conditions and producing large gelatinous masses, are so far marked off from other cocci as to warrant, in our judgment, the retention of Cohn's genus. The genera Micrococcus, Streptococcus and Sarcina are retained, since in them morphological differences appear to be correlated with differences in biochemical characters or habitat and we have considerably enlarged the definitions of these genera to include physiological and ecological factors. With regard to the genus Diplococcus suggested by Weichselbaum for the parasite of pneumonia it should be remembered that any coccus may at times occur in pairs. Yet those organisms which are strictly parasitic and which normally occur only in aggregations of two cells appear to mark a valid group. The morphological character of a genus must never be too rigidly interpreted. It refers to the typical and most commonly characteristic growth forms; and other groupings may at times occur. Therefore, we recognize five genera, based in each case on a more or less constant association of several independent characteristics. The old genera Merispomedia and Staphylococcus are merely synonyms of Cohn's Micrococcus, and Ascococcus antedates Leuconostoc. Fischer's characterization of Pediococcus by regular division into two sections at right angles to each other, rests upon a variable and thoroughly artificial character and probably includes some species of Micrococcus and some imperfectly studied species of Sarcina.

With regard to the genera, Planosarcina and Planococcus, founded upon the single char

acteristic of the possession of flagella there may be more uncertainty. The slow revolu tion and steady translation observed by AliCohen and Migula as associated with flagella, is certainly a phenomenon distinct from the irregular vibratory and rotary movements noted by other observers, but the resemblance between motile and non-motile forms is so close in all other characters that we can not consider this single property to be of generic importance.

The five genera above mentioned have been discussed first because their characteristics are already somewhat familiar; but in logical order the larger subdivisions should have been previously considered.

The family Coccaceæ, although defined only by the spherical form of the individual, is a thoroughly satisfactory natural group, its members being also marked off in certain physiological characters from individuals of other groups. The family appears to be divisible into two subfamilies. The first, for which we suggest the name Paracoccaces (paratrophic cocci), includes Diplococcus and Streptococcus, parasitic forms which do not develop abundant growth on artificial media and which thrive better under anaerobic than under aerobic conditions, and appear in small cell aggregates of pairs or chains. The second subfamily, the Metacoccaceae (metatrophic cocci), includes Micrococcus, Sarcina and Ascococcus, saprophytic or semi-saprophytic types which are aerobic and form abundant surface growths of large cell groups.

The species of the coccaceæ are considerably more obscure. We have reviewed the descriptions of 445 supposedly distinct species given by Cohn, Migula, Flügge, Chester, Sternberg, Lehmann and Neumann, Engler and Prantl, Rabenhorst, Frankland and Woodhead and find a wonderful amount of duplication. Our observations have convinced us that minute differences in morphology, as for example, the distinction between large and small cells or long and short chains, are not sufficiently constant for the erection of species. Again, slight differences in the appearance of colonies on gelatin, which form a large number of German species, vary