location, the northeast corner of the Olympic Peninsula, the matter seems worthy of record.

The find included two tusks in a fair state of preservation, one entire and one broken in two. The tusks were 64 and 64 3/16 inches long, respectively, the measurement being made on the outer curve. The diameter at the base was slightly over 20 inches. The weight was estimated at 35 pounds.

Just below the base of the tusks, which were in a horizontal position, were five teeth and a number of bony fragments, presumably of the jaw. One tooth comprised five sets of triple protuberances which were well pointed. Another tooth comprised four sets of triple protuberances with a fifth small stub. The enamel in both of these was in good condition. The other three teeth, each three and one-half to five and one-half inches long, comprised three sets each of 'double protuberances, in one case worn down about three-fourths of an inch, in the second, worn slightly more, and in the third, the smallest of the group, worn to the base of the points.

The bones were found in the course of the digging of a ditch to drain a swampy area which has been a beaver swamp within the memory of the present inhabitants of the region. The following section was exposed in the trench:

a. peaty bog muck, 2 feet 0 inches; b. marly clay, 0 feet 1 inch; c. peaty clay, dark, 2 feet 6 inches; d. sandy clay, fossiliferous, 1 foot 0 inches (base concealed).

The fossils have not been studied, but include abundant fragments of minute gastropods and other shells. The mastodon remains were in the layer c. approximately three feet below the present surface of the swamp, which is not far above sea-level.

HAROLD E. CULVER

STATE GEOLOGIST OF WASHINGTON

AVAILABLE MATERIAL IN COMPARATIVE ANATOMY AND PATHOLOGY

THE Laboratory of Comparative Pathology of the Philadelphia Zoological Society has rather extensive material of anatomical and of pathological character, some of which is not entirely used by the laboratory personnel. It has been our policy to supply to accredited investigators a moderate amount of material for their problems.

I am writing this letter to make it more generally known that material is available, because we wish no opportunities lost to be of service to workers in these general lines. This material will be given to research and teaching institutions that receive the approval of the American Association for the Ad

vancement of Science. It will be sold to dealers whose business it is to distribute material.

Since this laboratory has no shipping department, it will be necessary for workers who desire material to supply us with mailing and express cases suitable for the specimens they desire, and to pay postage and expressage. The laboratory can not engage to embalm or inject tissues free of charge, but may be able to undertake small problems of this kind for the time-cost of the labor.

There are now available a moderate number of male and female genital tracts and of intestinal tracts. A few central nervous systems and ductless glands may also be supplied, but many of these in our laboratory are already preempted. The group specimens are grossly normal, but have not been investigated microscopically.

In so far as pathological material is concerned, the laboratory will supply only what develops in the routine autopsies and is not needed for museum purposes. Specimens needed for the collection, and those already mounted for the museum will not be supplied. HERBERT Fox

THE ZOOLOGICAL SOCIETY OF PHILADELPHIA

REPORT OF THE RANSOM MEMORIAL

COMMITTEE

THE Committee which has been in charge of the establishment of a memorial to the late Dr. Brayton H. Ransom, after a careful study of the opinions expressed in answer to a questionnaire on the subject and a consideration of the limitations placed on the choice of a memorial by the size of the fund, has come to a decision as to the form to be taken by the memorial. It has been decided that the fund be invested and that the interest be used as a money prize of $100 when that amount is available, to be awarded by the committee to a person of any nationality who has not passed his fortieth birthday at the time of the award, and who has made a comparatively recent noteworthy contribution in the field of parasitology.

The fund at present totals $930 in actual subscriptions and $135 in unpaid pledges, approximately 100 persons, representing fifteen countries in addition to the United States, having cooperated in bringing the fund to its present status, the individual contributions ranging from $1 to $100.

The fund has thus far been kept in a savings account drawing the usual interest, in the hope that a $1,000 total might be actually available for investing in a more remunerative manner; the question of investment is now being carefully investigated by the committee.

It is hoped that outstanding pledges will be paid in the near future and that any persons still desirous of joining in the establishment of this memorial to Dr. Ransom will not delay longer.

ELOISE B. CRAM, Secretary, Ransom Memorial Committee BUREAU OF ANIMAL INDUSTRY, WASHINGTON, D. C.

SCIENTIFIC APPARATUS AND LAB

ORATORY METHODS

A SIMPLE DEVICE FOR WASHING CULTURE TUBES

ONE of the most irksome and time-consuming operations of the bacteriological laboratory is the washing of culture tubes. Recently, we have been using a very simple piece of apparatus which has proved to be so satisfactory in this laboratory that we believe others will find it useful.

The device consists of a water-motor which attaches directly to the faucet by means of a screw connection. A 4-inch motor furnishing 8 h. p. on 80 pounds water pressure with a free speed of 4,500 revolutions per minute is used. Because of its simplicity, cheapness and ease of control this motor appears to be more satisfactory for the purpose than an electric motor. The test-tube brush is attached to the motor shaft by means of a metal chuck. We have found it more satisfactory to employ only about two inches of the bristle-tipped portion of the brush in a chuck about six inches long. This arrangement causes the brush to revolve steadily when running free and facilitates insertion into the tube. Brushes with straight bristle-tipped ends have been found more satisfactory than the newer kinds with the so-called "spray tuft" end. After the tubes have been given the preliminary preparation for brushing they can be handled rapidly and with much less breakage than by the method of hand brushing. The rate should approximate 800 to 1,000 tubes per hour.

So far as we are aware none of the supply houses is furnishing the complete apparatus at the present time. The chuck we are using can be made in a few minutes from a piece of brass rod of suitable size for attachment to the motor shaft and turned down to a diameter of about 1/4 inch. A hole drilled in the end of the rod receives the brush wire, which is held in place by means of a screw. The entire apparatus costs only a few dollars.

UNIVERSITY OF TEXAS

I. M. LEWIS

SPECIAL ARTICLES

NOTES ON A SPECIES CROSS IN MICE AND ON AN HYPOTHESIS CONCERNING THE QUANTITATIVE POTENTIALITY

OF GENES

SPECIES crosses in laboratory rodents are not very numerous. That of Cavia rufescens Lund. and C. porcellus Linn. reported by Detlefsen,1 and of Rattus rattus × R. alexandrinus studied by de L'Isle ('65),' and of Morgan,3 are among the more important.

The present note deals with a cross between males of Mus wagneri (Eversman) from China and tame Mus musculus females of a dilute brown race which has been inbred brother to sister in my laboratory since 1909.

Mus wagneri is small, nervously active, with relatively long ears and short tail, and is white-bellied, black agouti in color. This color variety was first described genetically by Cuénot as a "gris à ventre blanc." It is allelomorphic and epistatic to ordinary grey-bellied black agouti.

The hybrids were easily obtained, grew vigorously, and were intermediate in size between the two parent species. In color they were species. In color they were white-bellied black agouti, but with deeper pigmentation than that of M. wagneri. In many of them the proportion of black hairs on the dorsal surface was very high, suggesting a weakened condition of the agouti pattern. The same tendency was seen in the ventral surface where dark-tipped hairs frequently were found in areas which in contrast to the white-tipped hairs gave a pattern which we have described as a "vest." It is extremely interesting to note this condition, which will again be referred to.

1

The three recessive genes of the dilute brown M. musculus females-a. (non agouti), b. (brown) and d. (dilution) disappeared in F, just as they would have done had the white-bellied black agouti pattern of M. wagneri been that of the same color variety of M. musculus.

A back cross of F, males and dilute brown females showed segregation of the three genes. The eight classes listed below were expected in equal numbers. The actual figures, however, depart widely from equality as follows:

1 Publ. Carnegie Inst. of Wash. (1914) No. 205. 2 Arch. f. Rassen u. Gesellschafts Biologie (1911) 8; 697.

3 Am. Nat. (1907) 43; 182

4 I am greatly indebted to Dr. Sheo Nan Cheer, who personally brought with him from China the live specimens of M. wagneri which form my breeding stock of that species.

5 Arch. Zool. Exp. et Gén. (1911) 8, 40-56.

If the pairs of genes are considered separately, we find that there are 94 animals with gene B(black) and 69 without it. There are 96 with gene D (intensity) and 67 with d(dilution), while there are 81 with A (agouti white belly) and 82 with a (non-agouti). Obviously the chief excess is found in black or intense animals. When these two genes are found together it appears that there are 61 animals, while those with (b) and (d) number 34. Those with (B) and (d), 33, and those with (b) and (D), 35. A somewhat similar excess of animals which had both (B) and (D) was observed in a cross reported by the writer and Phillips, between color varieties within the species M. musculus. It is probable that it depends upon death of recessive color combinations rather than upon any linkage or other gametic disproportion.

6

The "vested" variety is an extremely interesting "phenomenon. What perhaps is a somewhat similar condition in that it involves a "weakening" of the Tagouti pattern was observed by Detlefsen in the case of the guinea pig hybrids referred to above. In his material almost complete disappearance of "ticked" hairs was observed on the dorsal surface in some hybrids. The same phenomenon has been observed in the mice.

1

Morgan reports a weakened condition of the black factor in F, generation mice produced in a cross between a small Japanese-waltzing male and a larger brown non-waltzing female. It is interesting to note that Japanese-waltzing mice are, by many, believed to be descended from M. wagneri (see Gates').

At all events we have in three crosses, two of which do, and one of which may involve specific differences, distinct evidence of "weakened" activity of three epistatic genes introduced by males of the smaller species or variety.

This suggests an interesting line of reasoning as follows:

In addition to the qualitative attributes which distinguish it, each gene may have a quantitative potentiality adapted by natural selection to the size of the body which its activity must cover.

Since activity of genes in development is undoubtedly related in some way to liberation of energy, and since liberation of energy means previous storing of energy, it seems likely that a species will by natural 6 Am. Nat. (1913) 47, 760-765.

Publ. Carnegie Inst. of Wash. (1926) No. 337.

selection eliminate those individuals wasteful enough to build more of such potential activity than is commonly called upon. This would follow since surplus material would require additional food and storage space and would tax more than was necessary the systems by which waste products of metabolism were eliminated.

When a species cross is made resulting in an F1 hybrid of distinctly larger size than that of the small parent species, the genes of the latter adapted in their physiological activity to covering only a certain more or less limited body area, may find themselves unable to act over the whole of the body of the larger hybrid, and as a result the recessive gene would partially express itself. Such was actually the case in the three crosses referred to. The rôle of the cytoplasm in determining the degree or extent to which the gene may act is also possibly a matter of great importance in this connection. Data on reciprocal crosses in the three cases in question are not as yet available.

The principle of the quantitative limits of gene activity will, if established, be an interesting line of research to follow in size inheritance and in many other genetic problems of birds and mammals.

LABORATORY OF MAMMAL GENETICS, ANN ARBOR, MICH.

C. C. LITTLE

THE ABSORPTION SPECTRUM OF MERCURY
AT HIGH PRESSURE ADMIXED
WITH NITROGEN1

A CONSPICUOUS feature of the absorption spectrum of mercury, as shown by Mohler and Moore,2 is the appearance of a train of eighteen flutings reaching their optimum range of 2770-2930 A at 420° C. (2100 mm.).

In the present work, when 13 mm. of pure nitrogen gas was admitted to the same 40 cm. quartz absorption tube before sealing off and spectra photographed using the same source of radiation (a high potential discharge in hydrogen), this system of flutings was extended on the red to 3087 A at temperatures of 215-305° (28-215 mm. Hg) and on the violet to

1 Publication approved by the Director of the U. S. Bureau of Standards, Department of Commerce.

2 Mohler and Moore, J. Optical Soc. Am. 15, p. 74 (1927).

2666 A at 425-530° (1820-7250 mm. Hg). The longer wave length bands (3087, 3063, 3042, 3000, 2980, 2962, and 2944 A) show an average frequency separation of 225 cm.-1, nearly double the intervals obtained with pure vapor. Some 32 bands were found within the range 2919-2666 A at higher pressures, with a wave length separation of 12 A at the beginning and 5 A at the end of the series. Seventeen of these bands within the range 2762-2666 A represent a definite extension on the short wave length side to those previously reported.

Lord Rayleigh3 has announced the occurrence of fifty absorption bands in the region 2697-3055 A with a long column of vapor. Altogether 42 such bands were found in the present work with 13 mm. of nitrogen, and the increase of 24 (42-18) indicates that nitrogen does exert a specific rôle, although it may not be a determining factor with a long vapor column. A shorter band at 2528 A, however, was always obtained with mercury-nitrogen mixtures and appears to be very definitely conditioned by the presence of this gas. This new band was seen within the temperature limits 230-430° C. with 13 mm. of gas, but appeared only at temperatures less than 250° (77 mm. Hg) with 30 cm. of gas. In runs made with a 90 cm. Pyrex tube provided with quartz windows, the 2528 band invariably was found to appear at temperatures below which the resonance broadening on the violet did not become greater than 9 A, thus overlapping and fusing with this band. Nitrogen pressures of 13 mm., 30 and 50 cm. were used in these trials. Pressure conditions, however, were much less definite than with exposures taken with the 40 cm. quartz tube.

Data procured from the present photographs on resonance widths at various temperatures confirm R. W. Wood's first qualitative observations on the symmetrical broadening of resonance absorption at intermediate pressures, and asymmetrical broadening (i.e., towards the red only) at higher pressures for mercury vapor admixed with a foreign gas. It is evident, however, that widths found at lower temperatures (150-250°) are misleading if no allowance is made for the 2540 and 2528 bands. The present measurements show that resonance broadening increases with the pressure of nitrogen. At 350° with

30 cm. of nitrogen, a maximum displacement of 32 A to the violet was obtained. The displacements toward the violet with 13 mm. of nitrogen are only 2-4 A in excess of blank trials made without gas. Broadening toward the violet in the presence of nitrogen is a very complex phenomenon, but bears no evident rela

3 Rayleigh, Nature 119, p. 778 (1927). 4 Wood, Astrophys. J. 26, p. 41 (1907).

tion to the appearance of new spectral bands. Nitrogen, even at high pressures, does not seem to hasten markedly the rate of broadening on the red at high temperatures. Born and Franck's5 concept of three body collisions may be applicable in this connection, for it is clear that a red quantum will suffice to raise the Hg atom to the 3P, state if the impacting nitrogen molecule or mercury atom contributes the necessary energy difference at the expense of their own translational energy. Such a picture is dynamically impossible for broadening on the violet.

1

The action of nitrogen in developing new spectral bands admits of no clear-cut interpretation. The 2528 band, evidently characteristic of mercurynitrogen mixtures since it appeared with all pressures of nitrogen, can not be correlated with the additional flutings obtained only with 13 mm. of nitrogen. Paul D. Foote, in his very recent quantitative treatment of the mechanisms involved in the quenching of resonance radiation by foreign gases, has pointed out that Hg, molecules are produced by collision of excited mercury and normal mercury atoms and that the presence of nitrogen favors this process. In this case the extension of the fluting system may be ascribed to the increase in the concentration of Hg, resulting from the combined effect of the nitrogen and the radiation used as a source. This consideration, it must be noted, explains only the extension of the fluting series observed in pure mercury.

There is, however, another possibility. One might expect that high pressures of nitrogen and high temperatures would favor the production of unstable or quasi-stable HgN, molecules. Possibly such coupling occurs only between nitrogen molecules and excited mercury atoms. Foote's work suggests, further, that an optimum pressure of nitrogen produces a maximum number of 3P, Hg atoms. The life of the P state is inversely proportional to the pressure of nitrogen. An equilibrium eventually must be set up between the number of 3P, atoms produced and destroyed by nitrogen. Such considerations make it appear possible that the additional flutings on the red represent the vibrational spectra of HgN, molecules formed in this way. The absence of these bands with higher pressures of nitrogen is then a necessary consequence of quenching, by the gas, of 3P, Hg atoms. Obviously these hypotheses suggest many experiments, but circumstances made it impossible for the writer to continue the research.

BUREAU OF STANDARDS, WASHINGTON, D. C.

HOWARD R. MOORE

5 Born and Franck, Zeits. f. Physik. 31, p. 411 (1925). 6 Foote, Phys. Review 30, p. 288, September, 1927.

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Entered as second-class matter July 18, 1923, at the Post Office at Lancaster, Pa., under the Act of March 8, 1879.

HOSPITAL AND LABORATORY1

THE formal opening of this hospital and clinic is significant of something of far greater importance than throwing open the doors of a new building which is imposing and beautiful in its architectural details and perfectly adapted in its plan and equipment to the purposes for which it is intended. This occasion signalizes the inauguration of a great experiment, for which the erection of this magnificent building, the installation of the splendid equipment, and the gathering together of the trained men who are to work within its walls represent but the collection of utensils and apparatus to be used in the performance of the test. That such elaborate plans should have been prepared indicates that those who have been responsible for this great undertaking possess a profound and abiding conviction and belief in the probable correctness of the idea, the truth or falsity of which is to be tested. These intrepid innovators believe that that branch of knowledge which has to do with disease in man has reached a stage in its development which entitles it to occupy a dignified and important place in the group of subjects which the university considers its domain. The fund of information concerning disease has grown to a sufficient bulk, the methods devised for its investigation have become sufficiently accurate, the subject itself is of sufficient interest, and its importance in all that relates to human welfare is sufficiently great to justify the prosecution of its study as an aid in the interpretation of nature, and not, as in the past, only as a part of the discipline required for engaging in a practical profession. This idea is not new, it did not originate in the minds of those responsible for this experiment, it did not spring forth fully formed like Minerva from the head of Jove. There have been many preliminary experiments, Vorversuche, but here in this relatively young university, which has been the cradle of so many fruitful innovations in the field of education, this idea is to receive a trial with facilities worthy of the importance of the issue.

It is especially appropriate that this experiment should be made in this great institution whose own commencement involved not one, but many experiments. President Harper early spoke of this univer

1 Address delivered at the dedication of the Albert Merritt Billings Hospital and the Max Epstein Clinic of the University of Chicago, November 1, 1927.