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A mutation in the Cornell K-strain of White Leghorns, first recognized when two adult males in a pedigreed family were definitely smaller than their two other brothers, proved to be an autosomal recessive mutation and gave rise to the autosomal dwarf stock. The effect of this gene (adw) can be recognized during embryonic development and leads to a normal adult, except for a 30% reduction in body weight. Selection for small size, egg production, and egg weight over a period of 15 yr yielded an efficient layer. Production for 11 mo from first egg was at a rate of 70%, with egg weight at 56 g and body weight at 1,160 g at 10 to 11 mo of age, based on data for the last four generations. Viability of the caged hens averaged over 95% for the 13 generations involved. Sexual maturity was delayed by about 2 wk, and good incubation (85+%) required 18+/- more hours than normal. When an autosomal dwarf male is used as a sire and mated to sex-linked dwarf (dw) females, all progeny are of normal size. Compared with problems of mating normal size males with dwarf females, the use of the two types of dwarfism can yield good fertility.

We present the first results from the upgraded version of the scanning photoemission spectromicroscope MAXIMUM, bared on synchrotron undulator fight and on a multilayer-coated Schwarzschild objective. The upgrade involved nearly all parts of the instrument, notably the beamline and the electron analysis system. Micro-images of Fresnel zone plates and of metal test patterns on semiconductor substrates reached a new record in lateral resolution, well beyond 0.1 micron. The first spectromicroscopy tests were also successfully performed on the new instrument, with analysis of f and d core levels in different systems.

We describe here a unique lithography beamline that delivers x-rays using a flexible arrangement of two toroidal mirrors (one concave-concave and the other concave-convex), providing high spectral and spatial uniformity at the wafer plane. The image produced is a thin horizontal line, suitable for exposing a 25 by 50 mm field compatible with 0.25 μm VLSI. We also present the current status of the beamline being constructed at CXrl utilizing these optics.

When measuring optical radiation due to electron and ion bombardment of alkali halides, we have observed a broadband radiation pattern whose origin is not well understood. Though CN has been suggested as a possible source [1,2], some problems with this interpretation are encountered. Conditions under which the peaks were produced and some parameters which affect their intensities are reported here. We also include a description of our attempts to determine the source of the bands.

A technique has been developed for creating in the laboratory suprathermal, neutral atomic beams by means of grazing-incidence collisions between ion beams and metal surfaces. Residual ions are deflected by applied electric fields. The resulting neutral beams are pure, well-focused and mono-energetic. Energies from a few eV to tens of keV are obtainable. The technique permits the beams to be used in conjunction with electron and photon irradiation for studies of synergistic effects. Of particular interest is the creation of a low-energy, neutral, atomic-oxygen beam, which is of importance to space-related research.

The phenomena of spaceglow and material erosion, which are observed on spacecraft that orbit the earth at low altitudes, are described. Also described are the physical environment of the low earth orbit and the methods by which laboratory research on these phenomena is conducted.

A sex-linked dwarf strain of chickens fed a practical chick starter had a high incidence of rickets while other strains, including the Cornell K strain reared under the same conditions, had no evidence of this disease. In studies of the calcium, phosphorus and vitamin D requirements of the dwarf and K strains, no strain differences in requirement for phosphorus or vitamin D for maximal bone mineralization were apparent. The vitamin D requirement for growth was less for dwarfs than for the K strain; the reverse was observed for phosphorus. A marginal level of calcium (0.6%) did not depress growth or bone ash in either strain. Dwarfs had significantly lower bone ash than chicks of the K strain when dietary levels of calcium, available phosphorus and vitamin D were adequate (1.0%, 0.73% and 400 I.U./kg., respectively). When the diet contained a low level of one nutrient (0.6% calcium, 0.33% of phosphorus or 100 I.U./kg. vitamin D), neither strain was affected. Low levels of two nutrients significantly decreased bone ash in dwarfs but not in the K strain. Low levels of all three nutrients depressed bone ash in both strains, but most markedly in the dwarfs. These studies indicate that chicks of the Cornell dwarf strain have a low bone mineral content and are unusually susceptible to rickets.

The average coefficient of inbreeding after 35 years of development of Cornell S strain was estimated at 39% using pedigree data. Based on the number of breeders used and assuming that all breeders were one year old, the expected coefficient of inbreeding would have been 69%. The average age of breeders used in any one year varied between 1.05 and 2.36 years. It is suggested that the smaller coefficient of inbreeding was primarily the result of a decrease in the number of generations possible in the fixed time span of 35 years when the average age of breeders was greater than one year.

The discovery that neutral excited- and ground-state atoms are efficiently desorbed from alkali halide surfaces by both electrons and photons has raised a host of questions about the ways in which energy is absorbed, localized and redistributed in electronically-stimulated desorption. We present recent measurements of electron- and photon-stimulated desorption of neutral alkali atoms from LiF and NaCI which attempt to answer these questions by providing details of energy dependence, velocity distributions and variations in the desorption yield as a function of surface temperature. The ground-state neutral desorption dynamics under both electron and photon irradiation are consistent with a model in which halogens are ejected from the surface in a focused collision sequence, while the neutral alkalis are desorbed thermally. However, the excited-state neutrals do not follow this pattern, and further measurements to understand excited-state neutral desorption will be necessary. The implications of the experimental data for an understanding of the desorption mechanism-such as correlations with specific core-level excitations and with mobilities of electronically-induced defects-will be discussed.

INTRODUCTION WHILE there is general agreement that some degree of heterosis is to be expected from crossing different breeds, and also from crossing inbred strains of one breed, there is still much to be discovered about (1) the ways in which that heterosis may be shown and (2) the amount of inbreeding of parent strains that is necessary to induce it. This report presents some evidence on both of these points. It comes from reciprocal crosses made in two successive years between two strains of White Leghorns which, although maintained for some years as distinctly separate strains, were only slightly inbred. STRAINS CROSSED The Leghorns crossed were of the C-Resistant and K-Resistant strains which, since 1935, have been bred by the authors for resistance to leucosis and, concurrently, for increased egg production, for eggs of about 58 to 60 grams, and for a body weight of about 2,000 grams. Details . . .

THE size of the comb in different breeds bears no direct relationship to the inherited ability to live and to lay. However, within any one breed the extent to which a rather large comb might interfere with feeding or be more prone to injury could indirectly affect a bird’s health or production. Dubbing to improve a cock’s chances in the fighting pit has been practised for a long time, and in colder climates males are often dubbed to eliminate the adverse effects of a frozen comb and wattles on vigor and fertility. It is surprising, therefore, that the dubbing of females has not received consideration until recent years. Perhaps the first attempt to evaluate the effects of dubbing females was that of an unknown poultryman who reported his findings in the Australian Poultry World. These were summarized subsequently by the Editor of the New Zealand Poultry World (Anonymous, 1942). In …

HUTT and Scholes (1941) have shown that adult White Leghorns are significantly more resistant to pullorum disease than are the adults of heavier breeds such as Rhode Island Reds, Wyandottes, and Barred Plymouth Rocks. Furthermore, they showed that newly-hatched White Leghorn chicks display a greater resistance to pullorum disease than do chicks of the Rhode Island Red and Barred Plymouth Rock breeds. This resistance is undoubtedly accompanied by some physiological or morphological phenomenon which the White Leghorn breed possesses to a greater degree than the heavy breeds. Schnetzler and Hartsell (1940) have reported that adult White Leghorns and Rhode Islands Reds differ in the bactericidal power of the sera of their blood. They found that the more resistant Leghorns had greater bactericidal power and suggested that this greater bactericidal action on the part of the sera of the White Leghorn fowl might account, at least in part, for the greater . . .

IN RECENT years considerable attention has been drawn to a newly recognized genus of gram-positive organisms which apparently is responsible for a variety of pathological conditions affecting several species of animals, including man. In some species the organisms of the genus Listeria show a predilection for the central nervous system where they produce an encephalitis or encephalomyelitis. The literature on this subject has been recently reviewed in several papers, one of the latest of which is by Graham, Hester, and Levine (1940). The organisms of this genus have been associated with fatal infections of the central nervous system and its coverings in man, sheep, cattle, goats, and foxes. Organisms of this genus were first described under the name of Bacterium monocytogenes by Murray, Webb, and Swann (1926) as the etiological agent of a disease of rabbits which was characterized by a monocytosis. Recently some evidence has been accumulated to indicate . . .

THE diagnosis of blue comb on the basis of clinical symptoms, and gross and microscopic lesions, is fairly definite when the disturbance involves several birds in a population. It is much less so when only an individual bird is available for autopsy and the case history does not indicate a generalized flock condition. Blue comb, as a specific disease entity, has been recognized for several years and can cause considerable loss in the form of mortality, reduced production, and often from the failure of laying flocks to regain previous levels of performance. It apparently is not limited to any age group or season of the year, although many of the outbreaks occur among maturing pullets during the hot summer weather. CASE HISTORY Blue comb, as such, has not been a problem in the departmental flock at Cornell University for several years. About 1940, this disease affected newly-housed White Leghorn pullets, . . .

OVULATION and the subsequent laying of a normal egg, usually within 26 hours, are preceded and accompanied by certain changes in the body of the hen. The external characters that are associated with an active state of egg production are well known and are used as the basis for the periodic culling of commercial laying flocks. By the absence of external changes considered indicative of egg production, one is able to identify non-layers and to remove them from the flock, if so desired. It is customary to consider as layers those birds which show the external characteristics associated with egg production. We have learned, however, that some birds behave as though they were laying, and show appropriate changes in body condition, without actually producing an egg. This paper presents the pertinent findings when groups of such birds were subjected to study. SOURCES OF DATA Among large populations of pedigreed White …

The incidence of ventricular fibrillation during and after temporary experimental occlusion of the left anterior descending coronary artery or its branches was studied in 351 dogs. A standardized procedure of thirty-minute temporary occlusion of this artery was employed in 330. There is usually a critical period after twelve and up to fifteen minutes of ischemia which is characterized by a tendency to arrhythmia: extrasystoles, singly or in runs, ventricular tachycardia, or both extrasystoles and tachycardia if not a fatal ventricular fibrillation. Several instances of transient ventricular fibrillation were observed. Of 239 animals surviving thirty minutes of occlusion, 71 per cent developed ventricular fibrillation immediately after release of the artery, while only 28 per cent of 330 animals developed fibrillation during the occlusion. The re-establishment of blood flow to an area of the myocardium made ischemic for thirty minutes by occlusion of the anterior descending coronary artery is more likely to precipitate ventricular fibrillation than is the period of ischemia itself. Various drugs were evaluated in 324 dogs. Quinidine was the most effective drug in affording protection from ventricular arrhythmia during (7 per cent) and following (47 per cent) occlusion. Procaine, procaine amide and Apresoline offered good protection during the ischemic period. Apresoline and Regitine also reduced the incidence (44 and 37 per cent) of ventricular fibrillation upon reopening the ligature. Of the other drugs tested, only one, pendiomide, showed significant protection (52 per cent incidence). Systemic arterial pressures did not predict the onset of ventricular arrhythmia. Electrical countershock accomplished cardiac resuscitation in 75 per cent of the fibrillating dogs. From these experiments, quinidine appears to be the drug of choice in the prophylaxis of fatal ventricular arrhythmias.

DURING the first 8 years of selection at this laboratory for genetic resistance to leucosis combined with other traits of economic value, it was our practice to leave each male in his breeding pen throughout the entire hatching season of 8 to 10 weeks. By 1942 it was evident that, while marked improvement had been made in the first three years, progress thereafter had been almost nil. It was equally clear why improvement had stopped. We had tried each year to find enough good proven sires to head at least 25 percent of the breeding pens. During the first 5 years, the average number of pens used for the two resistant lines together was only 13.2, but, among the 10 cockerels or so tested annually, it was seldom possible to find 3 or 4 proven sires that could be used again without considerable misgivings. In 1940 to 1942, the average …

INTRODUCTION FOUR years ago, Hutt et al. (1941) reported results for the first four generations of White Leghorns bred for resistance to disease, particularly to lymphomatosis. These showed that, whereas deaths from neoplasms during the test period were 16 percent in the unselected population with which the experiment started, in the fourth generation such deaths had been reduced to 12 percent. This decrease, really by a quarter of the original proportion, seemed significant, not merely because it was based on 785 birds, but because, at the same time, deaths from neoplasms were more than twice as frequent (26 percent) in the stock bred for susceptibility. Moreover, the decline of total mortality from 64 percent in the unselected population to 38 percent in the fourth generation permitted a higher proportion of the latter to develop neoplasms had they been genetically susceptible. The fact that only 12 percent did so is more . . .

AS YET there is no critical evidence to show definitely that the agent of avian leucosis is or is not transmitted through the egg. There has, however, been accumulated considerable circumstantial evidence to support both possibilities, especially the former concept. This is not unexpected, because positive data are more likely to be published than are negative data. It is obvious that for a complete understanding of the avian leucosis complex more information as to the possibility of egg-borne transmission of the etiological agent must be provided. In order for the disease to develop, two conditions must be satisfied. The infective agent must be present and the host must be genetically susceptible. Natural (genetic) resistance is a relative factor and its normal expression can be overridden by an excess of the agent or exposure. Such happenings occur regularly and are responsible for variations in incidence of the disease within a flock . . .

IN A PREVIOUS communication by one of us (F. B. H., 1938), it was pointed out that neoplasms caused over 38 percent of all deaths among 1,922 fowls dying during the six-year period, 1931–37, at two laying tests in New York. It was also shown that in this same population 87 percent of all deaths were caused by diseases thus far not amenable to control by sanitation, immunization, elimination of carriers, and other orthodox procedures currently recommended for the control of poultry diseases. Because of this situation, an experiment was begun in the spring of 1935 to test the feasibility of breeding strains of White Leghorns resistant to some of these diseases. A brief report of the first three years of this work was given earlier by Hutt, Bruckner, and Cole (1939). In the present paper, we present results of the first five years’ work. These include the unselected . . .

DURING the last three decades considerable work has been expended in an effort to characterize the enzyme lysozyme and its action, details of which can be found in the excellent reviews by Thompson (1941) and Hartsell (1949). Although the egg white of the domestic fowl has long been accepted as a highly concentrated source of the enzyme, the variation existent in the egg white of different hens has not received attention. Indeed, some workers have used egg white as a standard reference in their quantitative measurements of lysozyme in other fluids and tissues. Recent evidence (Hawthorne, 1950; Feeney et al., 1952) suggests a primary role of lysozyme in the thinning of the egg white. All other avian species that have been tested thus far (Fleming and Allison, 1924; Smolelis and Hartsell, 1951) have been shown to have less lysozyme in the whites of their eggs than has the domestic fowl… .

THE persistent claim by Waters (Waters and Prickett, 1944; Waters, 1945; 1947) that avian leucosis is spread by transmission through the egg to the chick has now been extended to include a theory that chicks are infected in the incubator by dissemination there of the causative virus (Waters and Bywaters, 1949). These themes have received so much attention by the world’s poultry press that many poultrymen are now hoping to be able eventually to control the disease by the detection and elimination of hens carrying the virus or by disinfection of the incubator. In our opinion, the data presented hereunder show (1) that it is very unlikely that the disease is transmitted through the egg, (2) that any such transmission that may occur is of no significance whatever in the practical control of leucosis, and (3) that the all-important factors in determining the severity of this disease in a flock . . .

THE use of multiple shifts for testing large numbers of cockerels has proven of value as a method for recognizing superior sires (Hutt and Cole, 1955). Males proven to be superior by performance of approximately 50 daughters are then used in subsequent years throughout an entire breeding season of 8 to 9 weeks and produce families two to four times as large. The chief objection to the shifting or replacing of males in the breeding pens is that for a period of time the paternity of the chicks hatched may be in doubt. In practice, this uncertainty need not be a deterrent to the use of multiple shifts. The actual error in assignment of paternity is so low that it would not influence the evaluation of either parent. PREVIOUS REPORTS Crew (1926) exchanged males in two breeding pens and measured the speed with which the semen of the replacing male …

THE relationship between the iris color of the dam and mortality of her progeny is of considerable interest to the poultry breeder. This interest is prompted by the fact that an association of abnormal iris color of the dam and a high rate of mortality of the progeny would offer an immediate, practical means of reducing mortality. One of the most comprehensive studies of the subject has been that of Lee and Wilcke (1941). They demonstrated that females with pearl-gray irises which were irregular at the pupillary border gave progeny which developed symptoms of fowl paralysis more frequently than did the dams with normal eyes. This suggested that such females were transmitting the causative agent of lymphomatosis through the egg to the chick. Earlier, McClary and Upp (1939) had found that dams which were affected with iritis had a greater proportion of daughters with iritis than did dams with unaffected . . .

IT IS now generally recognized that there are two distinctly different means of reducing mortality in fowls from lymphomatosis and related diseases. One of these is to breed strains that are comparatively resistant. The feasibility of doing so has been demonstrated by Hutt et al. (1941) and by Taylor et al. (1943), but the utilization of this method is limited by the fact that few poultrymen are in a position to maintain the necessary exposure to the disease and to carry out over a period of years the progeny testing, with its inevitable record keeping, that is required in breeding of this kind. The other method is to rear the chicks in complete isolation from adult fowls during the growing period. The efficacy of this procedure was demonstrated experimentally by Kennard and Chamberlin (1936) and by Johnston and Wilson (1937). It has been confirmed in practice by many poultrymen. Disadvantages . . .

NORMALLY the hen will surround with egg albumen and enclose within shell any object of a sufficient size (mature ovum) which passes down the oviduct. In the normal physiological process of egg production the mature ovarian follicle ruptures along the stigma; the released ovum is then engulfed by the infundibulum and as it passes down the oviduct acquires the various layers of egg albumen, shell membranes, and shell. Through some fault in ovulation, weakness in ovarian structure, or excessive physical tension, an intrafollicular ovum may be released or torn intact from the ovary and when picked up by the infundibulum, provides the necessary stimulus for physiological activity of the oviduct. The production of double-yolked eggs containing, in addition to the normal ovum, an intrafollicular ovum with stalk protruding through the shell at the larger end of the egg have been reported by Laboulbene (1859) and Hutt (1946), who also cited . . .

THE remarkable prophylactic and therapeutic value of sulfonamide drugs against certain types of bacterial and protozoan diseases has been amply demonstrated in the domestic fowl. It is not surprising, therefore, that these drugs have been used against pullorum disease by several investigators. Severens, Roberts, and Card (1945) found that certain of the drugs, namely sulfadiazine and sulfamerazine, were quite effective in controlling mortality following the oral inoculation of day-old chicks with broth cultures of S. pullorum, even though feeding of the drugs was delayed for 3 days after inoculation. Similar results have been obtained by Bottorff and Kiser (1947) who fed the drugs for varying periods of time, starting with the day of inoculation. That sulfonamides can be of practical value under field conditions in which the disease has progressed far enough to cause losses and at least the presumptive diagnosis of pullorum disease obtained has been shown by Anderson . . .

Coles (1955) stated that “birds in their hen year failed to transmit resistance (to leucosis) because of incomplete ability to do so with increasing age” and that “a parent bird may increasingly fail with age to transmit genetic resistance to its offspring.” Age has no influence upon the genotype of an individual bird nor does it determine which genes are distributed to the functional gametes. Coles did not specify any mechanism by which age of the dam might influence resistance of her progeny, and the data given in support of his theory were scarcely conclusive. However, since in mice a non-chromosomal influence of age of dam on the incidence of spontaneous leukemia in her progeny is known (MacDowell, Potter and Taylor, 1945), it seemed desirable to examined our records for any evidence that might support Coles’s theory. From the records of our White Leghorns for the six years, 1949 to …

THE extent to which strains of fowls bred for genetic resistance to disease can be generally utilized depends in part on the answer to an important question. Are such resistant stocks equally or similarly resistant when transferred to areas other than that in which they were developed? With respect to unselected stock, there is ample evidence that strains which are satisfactory when lightly exposed in one environment can experience high mortality when severely exposed elsewhere. There is little evidence, however, on the degree to which strains bred for resistance to disease maintain that resistance when transferred to some other region. This question is particularly important with respect to leucosis, because genetic resistance and rearing in isolation are the only means known for controlling that disease. To answer it, in part at least, an exchange of stock was arranged between the Alabama and New York (Cornell) Experiment Stations, at both of . . .

IN A RECENT publication, Beach (1938) reports the results of experiments which he interprets as indicating a “failure to demonstrate the transmissibility of avian lymphomatosis by inoculation.” However, after application of the usual methods of statistical analysis there is little doubt but that he has demonstrated that transmission was accomplished. To test statistically the significance of Beach’s results, the writer has applied to them the χ2 test for significance of differences observed in a four-fold contingency table. The data for analyses (Table 1) are obtained by multiplying the cases per 10 birds (in Beach’s Table 2) by the number of birds in each group (in Beach’s Table 1) and totalling according to the strain and type of inoculum. To exemplify the method of analysis, the data for all experiments together (Table 1, line 5) are rearranged in a four-cell table as shown at the top of the next column. According . . .