Inches In Length Research Articles

Selenite crystals in the clays of Great Salt Lake [Utah

ABSTRACT Selenite crystals 2 to 6 inches in length have recently been found in a few places around the shores of Great Salt Lake in the soft sodium clays of the lake bottom. This occurrence may be significant in explaining the origin of selenite crystals in shales, so commonly seen on the erosion surfaces of shale formations in arid regions. Since the lake waters are impoverished in calcium ions, the selenite crystals have never been precipitated in historical times and are not believed to be a precipitate from the lake waters in times past. Bacteria may be the cause of a steady state in the clays conducive to the growth of the gypsum crystals, and physical changes incident to the consolidation of the clays may also be significant.

An example of parasitism among Polychaetes.

I HAVE observed a case in which the young of one polychsete annelid, Arabella—probably A. iricolor (Montagu), the cosmopolitan species which is common to the Woods Hole area—parasitizes another polychaete, namely, Diopatra cuprea (Bosc). On August 24, I recovered fifty-three complete worms of the genus Arabella, and the parts of approximately ten others from one adult Diopatra. The segment from which the parasites were recovered was approximately one and a half inches in length. The Arabella ranged in size from small worms of approximately thirty segments without eyes or setse to large worms with four eyes (arranged in the transverse row typical for the genus) and with numerous segments (up to approximately 180), some of which contained setae. The largest parasite was approximately 5 cm. in length, as compared with the adult Arabella, which ranged in size from 50 cm. to 60 cm. in length1. The larger parasitic Arabella appeared to lie free in the cœlom, whereas the smaller ones were held in place by the small parietal blood vessels in the body-wall of Diopatra.

Estimation of Fish Populations in Michigan Lakes

Fish population estimates, using trap nets in the Petersen mark-and-recapture procedure, were made during 1948, 1949, and 1950 on Sugarloaf Lake in Washtenaw County and during 1950 on Fife Lake in Grand Traverse County, Michigan. The nets were of two sizes: 3-foot and 6-foot. The lake acreages are 180 and 575, respectively. The important fish species were bluegill, pumpkinseed sunfish, yellow perch, largemouth bass, smallmouth bass, black crappie, northern pike, yellow and brown bullheads, and warmouth. The study was limited to fish over 6 inches in length. In four separate netting periods, 17,887 fish (approximately half bluegills) were marked by fin clipping and released, and 2,991 of these (17 percent) were recaptured. Distinctive markings were used for fish from two halves of each lake, and recaptures were tabulated accordingly. Marked fish, liberated at a common release station near the center of the lake, showed a tendency to return to the same half of the lake where marked; but the amount of this “homing” was not sufficient to invalidate the population estimations. Distinctive marking for two groups of stations, separated systematically according to even and odd numbers in series, gave returns which showed no marked tendency for fish to return to their home trap-net site. The three separate estimations of populations of legal-size fish in Sugarloaf Lake, computed by the Schumacher and Eschmeyer formula, gave 17,648 fish for the fall estimate of 1948, a total of 15,531 fish for the spring estimate in 1949, and 22,178 fish in the spring of 1950. These totals, correlated with the numbers of trap-net stations on which the estimates were based (30, 20, and 40, respectively) suggest, by extrapolation, that the true population figure is something less than 30 thousand. The average computed total for the 3 years was 18,452 fish, or 102 fish and 43.1 pounds per acre. Estimations by the Schnabel formula gave totals which were generally a little higher than by the Schumacher and Eschmeyer formula. For Fife Lake the estimated total population was 99,056 fish or 172 fish of 62.3 pounds per acre. In both lakes the bluegill made up over half of the totals. Records of marked and unmarked fish in anglersˈ creels immediately following the trap netting provided another basis for estimating the fish populations in Sugarloaf Lake in 1949 and 1950. Such estimates were about double the estimates based on trap-net recaptures. The reason for the difference was not determined.

Low‐temperature rubber: Emulsion polymerization in a salt antifreeze system

AbstractButadiene‐styrene copolymers have been prepared at subfreezing temperatures by means of redox recipes employing inorganic salts as freezing point depressants. Specific salt‐emulsifier combinations are required for optimum rates of polymerizations. With a sufficient amount of the inorganic salt to lower the freezing point of water 10°C., the sodium chloride–potassium caprylate combination resulted in a 60% conversion in 4.6 hours, the calcium chloride–sodium hexyl sulfate combination resulted in a 41% conversion in 24 hours, and the calcium chloride–alkyl aryl polyether alcohol combination resulted in a 58% conversion in 18.5 hours.Low molecular weight mercaptans such as tert‐butyl mercaptan can be employed as practical modifiers for this recipe.Certain of the physical properties of the salt antifreeze copolymers prepared at −10°C. are superior to those of copolymers prepared at the same temperature by means of conventional recipes. The ease of processing and the heat‐aged properties are exceptional. One copolymer after 24 hours of aging at 100°C. withstood 118,000 flexures before a puncture increased to one inch in length at 99°C. The superiority of the product is attributed to the precipitation of the copolymer during the course of the polymerization.

A Stereoscopic Viewing Desk Designed for Limited Space

With the opening of the new Sunnybrook Hospital by the Department of Veterans Affairs of Canada, one of the problems which presented itself was the optimum disposition of viewing equipment and office furniture in some offices as narrow as 9½ feet. Since a conventional Wheatstone stereoscope occupies a space 2 feet wide by approximately 7 feet long, many of the radiologists neglected the advantages of stereoscopic viewing because of the awkwardness entailed. In one of the offices, the problem has been solved as demonstrated in the accompanying illustration. In two of the others, slight modifications of this scheme are being tried. The desk part measures 21 inches from back to front, 31 inches in height and 64 inches in length. At the back of this desk and extending about one foot beyond it on the left side is a small platform with rails for the mirror system. In the center of the desk is the stereo view box system consisting of two viewing areas 11 3/4 inches square, inset so as to be flush with the table ...

The American Smelt, Osmerus Mordax (Mitchill), of South Bay, Manitoulin Island, Lake Huron

A smelt fishery established on the streams and freshets flowing into South Bay during the 1948 spawning run yielded a total of 51,382 pounds to local fishermen using dip-nets and seines. The smelt taken averaged 5.7 inches (145 millimeters) in fork length and 0.73 ounce (20.6 grams) in weight. Age-group II comprised 54 percent of the catch and age-groups III and IV 38 and 8 percent, respectively. Age-group II averaged 5.4 inches in length, age-group III 6.1 inches and age-group IV 7.2 inches. The estimated egg content in five fish ranged from 9,650 to 27,600 and was not entirely dependent on size. Some general observations on the food and spawning behavior of the smelt are also presented and comparisons with other populations made.

Trends in fluorescent lamps

A slender green tube 18 inches in length, introduced to illuminating engineers in 1935, is the progenitor of today's vast fluorescent lamp industry. Since that time, the basic methods of operating the tube have changed little. Engineers have improved and elaborated on fundamental system elements, such as ballasts, starters, and cathodes; as a result of their work, a large variety of lamps is available to the public.

Current Trends in State Fishery Programs

Abstract A questionnaire survey of the various states was made in June of 1946 to determine the current trends in fishery programs. Trout states total 31, with 246 hatcheries producing 203,546,000 fry and fingerlings and 18,081,000 creel-sized trout. The trend is to more creel-sized trout. States take 194,000,000 eggs themselves and obtain 98,375,000 trout eggs from other sources. A majority of states classify results of fry plantings as poor and of creel-sized plantings as good. The average creel-size trout is 7 1/2 inches in length and is 13.2 months old. The cost per pound for food alone averages 14.6 cents. Total cost per pound for raising trout averages 66 cents. Rainbow trout constitutes 47.5 percent of all trout raised, followed by cutthroat, 15 percent; lake trout, 13.4 percent; brook, 12.2 percent; and brown, 11 percent. Hatchery disease loss averages 13.5 percent. Gill disease seems most prevalent. The principle trout-culture problem is food, either procurement or proper diet selection. Floods a...

The Eastern Belted Kingfisher, Megaceryle Alcyon Alcyon (Linnaeus), in Relation to Fish Management

The kingfisher is the most common and universally distributed bird predator of fish in Michigan. Its principal migration routes are along the Great Lakes shores. Nesting territories are established along streams and lake shores; they are usually larger in the former than in the latter. The kingfisher is diurnal in its feeding with three peaks of activity–morning, afternoon, and early evening. First feeding of fledgelings is on insects; this food is followed by crayfish, then by fish. Fish eaten average about 2.3 inches in length and at fish hatcheries are mostly the species being propagated. On natural waters the food consists mostly of non-food and non-game fishes and crayfish. Predation pressure varies with season and within season according to weather, nest distribution, and environmental suitabliity of waters for feeding activity. Because of their feeding proclivities, it is undesirable to have kingfishers about fish hatcheries and rearing stations. At present, general control on natural waters is not biologically justified.

A Method of Roentgenologic Examination of the Shoulder

Calcifications in the soft tissues are often seen in roentgenograms of the shoulder girdle. Fractures with separation of small cortical spicules of bone are not infrequent findings. Tendon injuries, as rupture of the supraspinatus tendon and dislocation of the long head of the biceps brachii, are also known to occur. On occasion, the roentgenologist may be called on to localize accurately such particles and other abnormalities. Stimulated by necessity, the authors early became aware that the usual roentgenograms of the shoulder, namely anteroposterior views with the hand in supination and pronation, are insufficient, even if taken in stereoscopic pairs. The great freedom of motion of the humeral head on the surface of the glenoid fossa actually adds to the difficulty of the exact localization of a lesion. Anatomically the freedom of motion of the humerus is favored by a relatively loosely enveloping joint capsule, which attaches to the glenoid rim above and to the anatomical neck of the humerus below. This joint capsule extends in a tubular sheath enveloping the long head of the biceps brachii in its passage through the bicipital groove. Two layers of muscle overlie the shoulder girdle: the outer group, passing over the shoulder to insert into the upper humeral shaft, consists of the deltoid, pectoralis major, latissimus dorsi, and teres major; the inner group, the so-called short rotators of the shoulder, include the supraspinatus, infraspinatus and teres minor inserting into the greater tuberosity, and the subscapularis, inserting into the lesser tuberosity. The subacromial bursa, somewhat smaller than the palm in a given individual, fits like a skullcap over the lateral aspect of the shoulder between these outer and inner muscle planes, obviously so located to prevent friction from contrasting movements (Codman, 1). Because small calcifications so frequently appear within the short rotator tendons and periosteal proliferation may occur at the site of their insertion into the humerus, and because small bone fragments may actually be separated from these insertions, it is important to elaborate. The short rotator tendon insertions are broad and flat, measuring about an inch in length. They fuse into a continuous band or, better, interdigitate with one another. Fibers of this tendinous cuff are incorporated with the joint capsule proximal to their insertion. The greater tuberosity of the humerus forms an arc from before back, with its anterior margin bulging externally and sloping downward and forward for the insertion of the supraspinatus muscle; in the mid sector of this greater tuberosity a flat cortical plate of fingernail size slopes caudad externally and forms the facet for the infraspinatus insertion; and the less prominent posterior slope of the greater tuberosity marks the site for the insertion of the teres minor. The lesser tuberosity anteriorly (for the subscapularis) is a prominent “nubbin”-like projection.

Fossil Fauna in Norfolk

DISCOVERIES of no little interest to palæontologists and archaeologists are reported from Norfolk. During the past winter and early spring, the effects of marine erosion on the cliffs around the coast have been severe, causing much local uneasiness. In compensation, as a result of this tidal action, early quaternary deposits at the base of the cliffs and on the foreshore have been laid bare to an exceptional degree. At Mundesley, in particular, the Cromer Forest Bed is exposed more extensively than has occurred for a very long period and a number of discoveries have followed. Early in May, a fossil bone protruding at the base of the cliff was observed by Mr. E. A. Livermore of Mundesley. On extraction, this proved to be the major portion, a little more than three feet in length, of an elephant's tusk. It has since been identified as belonging to the extinct straight-tusked elephant, Elephas antiquus. A few days later, Mr. Livermore also recovered from close to the position of his first find part of a tooth, about six inches in length, of an elephant of the same species. Further discoveries were two fragments of bone, the tips of an elephant's femur and tibia respectively. A remarkable tooth, which belongs to E. meridionalis, also from the Cromer Forest bed at Mundssley, has been found by Mr. A. Savin of Cromer. It is complete, and weighs twenty-five pounds. With one exception, a tooth of twenty-six pounds, it is said to be the largest meridionalis tooth recorded.

A Stone Effigy from Long Island

In 1940, at Great Neck, Long Island, Mr. Calmer Forsander found a waterworn glacial cobble with a crudely executed face on one side in an old stone wall bordering his property. Mr. Forsander knew that I had excavated the Baker Hill site, located about three hundred yards west of his house, and brought the find to my attention. The specimen is roughly egg-shaped and is composed of a crystalline material which appears to be indurated sandstone (Fig. 24). It measures approximately IS inches in length, 11 inches in width, and 10 inches in thickness. On one of the broader sides is a face, pecked and ground into the surface. The workmanship is crude and resembles that found on the pitted hammer stones common in the region.

A New Pocket Prismatic Microscope

No extract is available for articles shorter than 400 words.

APPARENT LOCALIZATION OF FUSARIUM WILT RESISTANCE IN THE PAN AMERICA TOMATO

THE HIGH degree of resistance to the wilt disease caused by Fusarium oxysporum f. lycopersici Snyder and Hansen, in the tomato variety Pan America introduced by Porte and Walker (1941), has been proved by many laboratory and field tests. The near immunity is equal to that of the most resistant lines of Lycopersicon pimpinellifolium (Jusl.) Mill., the wild host which was used as a parent of Pan America. Grafting has been used to study the nature of disease resistance in several plants (Bond, 1936; Leach, 1929; May, 1930; and Schmidt, 1933), but in the experiments dealing with wilt resistance in tomatoes the varieties used as resistant are now recognized as having a much lower degree of resistance than Pan America. In the experiments reported here Bonny Best, a variety long recognized as very susceptible to the tomato wilt fungus, and the resistant Pan America variety were used. L. pimpinellifolium plants were used in one experiment. MATERIALS AND METHODS.-The seeds were planted in flats of one-half composted soil and onehalf sand mixture. After the cotyledons were fully expanded the seedlings were transplanted to 2?/2inch pots. When the plants were about three weeks old they were used for grafting. Two types of grafts were used-stem approach grafts and stem splice grafts. The approach grafts were made by removing a thin section about one inch in length, between the cotyledons and the first leaf, from adjacent sides of the two stems. The cut surfaces were immediately placed against each other and securely wrapped with a rubberized paraffin tape known as Parafilm (fig. 1). The graft components were both left intact until the plants were examined for wilt. The splice grafts were made by severing the two plants with a smooth slant-

Tumor-bearing Chicks Hatched from Eggs Inoculated with Mouse Carcinoma.

Taylor, McAfee, and Taylor state that chicks may hatch from eggs inoculated into the yolk with mouse mammary carcinoma. Using a slightly modified Taylor technic,, fertile eggs were inoculated on the 5th day of incubation with minced, or pressed mammary carcinoma of strain A mice. All materials used came from tumors arising originally in this strain and having a variable number of transfers in the strain. Mouse transfers were done using sterile technic. Tumor-bearing mice were killed with ether and the skin sterilized with iodine. Separate instruments were used for skin dissection and manipulation of the tumor. Pressed tumors were forced through muslim supported by a drilled, bras plate. Minced tumors were cut with very sharp fine scissors without addition of fluid. In both cases Tyrode solution was then added to give a suspension of about the same density as that used by Taylor. The shell over the air sac was wetted with 70% alcohol and after drying was cut through with a round dental, burr, turned by a high speed electric hand tool, care being used not to cut through the shell membrane. The membrane was wetted with alcohol and allowed to dry. The membrane was then burned through with a hot, tapering probe large enough to fit tightly into the hole in the shell, thus sterilizing the shell against which the needle subsequently touches. The suspension was inoculated into the yolk using a tuberculin syringe and a No. 20 needle 11/4 inches in length. The amount of suspension injected varied from 0.1 to 0.6 cc. All procedures were carried out aseptically. The hole in the shell was sealed with vaseline-paraffin mixture. Eggs were incubated at 38°C.

A Corner-Tang Artifact from Oregon

During the cataloging of a collection of some 650 tiny projectile points from the banks of the Columbia River in Columbia County, Oregon, an unusual specimen was brought to light. All but five of the points in the collection are under 3/4 inch in length and are proportionately narrow and thin. The five larger specimens were, then, immediately outstanding. Of these, one is of the corner-tang variety. It is 2.13 inches long, 1 inch wide, and 0.36 inch thick. It is made from a tan, slightly opalitic chalcedony,8 a material which is quite common in the collections of chipped stone artifacts from the lower Columbia River area.The specimen is of the type that Patterson has called “diagonal corner-tang” and possesses a small crescent notch on the side opposite the tang. The tang is quite narrow and pointed. The chipping is somewhat rough and uneven, and on one side there appears to be something of a channel groove running approximately two-thirds the length of the specimen. This is, in all probability, quite accidental.

Vegetative Propagation of Taraxacum kok-saghyz with the Aid of Growth Substances

1. Root cuttings of more than 9000 plants of Taraxacum kok-saghyz were used in experiments during December, January, February, and March, 1942-1943, to determine the response of cuttings to variations in propagation methods and to applications of β-indolebutyric, naphthaleneacetic, and naphthoxyacetic acid, and napthalene acetamide. Each compound was used in concentrations of 10, 50, and 100 p.p.m. in solution treatments and at 50, 200, and 1000 p.p.m. in talc dust. 2. The most desirable length of cutting was 1 inch, with a minimum diameter of 3/8 inch. Cuttings 1/2 inch in length were slow in callusing and rooting, while cuttings 3/4 inch long were somewhat difficult to handle and form into bundles. 3. The roots had strong polarity, and most pronounced rooting responses were obtained with cuttings set with the proximal portion up. Inverted cuttings failed to develop normally, while those laid horizontally were retarded in growth of tops and roots. 4. Under greenhouse conditions, cuttings with tops at or slightly above the level of the rooting medium developed new top and root growth more quickly than cuttings buried 1/4 inch below the surface. 5. Both sand and a light sandy soil were used as a rooting medium with equal success. The cuttings set in soil developed into sizeable plants over a 4-month period, while with similar lots set in sand it was necessary to remove them to soil at the end of 30 days. 6. Although root cuttings developed callus and top growth more quickly at 80⚬-85⚬ F., these cuttings were more susceptible to rot and the percentage rooted was lower than with similar cuttings maintained at 60⚬-65⚬ during the rooting period (21 days). 7. Treatment with growth substances by the solution methods resulted in an increase in the percentage of rooted cuttings in comparison with untreated controls. The optimum concentration for best results with the compounds used was at 50 p.p.m. with a 16-hour solution treatment. Each of the four growth substances and the mixture resulted in injury at 100 p.p.m. 8. The growth-substance-talc-dust treatments induced a higher percentage of rooted cuttings than was found in the untreated lots. At the highest concentration (1000 p.p.m.), however, rooting was less than with the same compounds applied at 50 p.p.m. in solution. 9. At the optimum concentration of growth substance for rooting (50 p.p.m.) indolebutyric and naphthaleneacetic acids produced a higher percentage of rooting than either naphthalene acetamide, β-naphthoxyacetic acid, or the mixture used. 10. The roots produced by cuttings following treatment with indolebutyric and β-naphthoxyacetic acids tended to be long and fine, while those which developed with napthaleneacetic acid and naphthalene acetamide tended to be short and much thickened.

Static Friction

Abstract A new machine is described by means of which static friction between contacting surfaces separated by lubricating films of thickness approaching molecular dimensions can be measured with considerable precision. In a test run, a number of spot determinations of the static coefficient are made at closely spaced points over a short rubbing track not exceeding a few thousandths of an inch in length. The individual “slips” at the contact may be as small as 0.0002 in. The unit pressure is of the order of 500 psi. A significant correlation between static friction and the molecular structure and dimensions of a pure hydrocarbon lubricant has been established. Exceedingly smooth contacting surfaces overlaid with monomolecular films of strongly polar hydrocarbons have exhibited the phenomenon of vanishingly low static friction.

Prawn Fisheries of India

DB. B. CHOPRA, in his presidential address to the thirtieth Indian Science Congress, Calcutta, 1943, has gathered together interesting information concerning the various Indian prawns of economic importance and their fisheries. There are many species of edible prawns in India, the most important and largest being the so-called sea-prawns or Penæids. These apparently breed in the sea, the young migrating to the lower salinities of backwaters, lagoons and estuaries to return again at maturity to the sea to hatch their eggs. Among the freshwater prawns the members of the Palæmonidæ occur in enormous numbers with extensive migrations from fresh to brackish waters, presumably for breeding. The tiny Sergestid Acetes, rarely more than an inch in length, makes up for its small size by its abundance and occurs in estuaries and backwaters, but rarely penetrates beyond tidal influence. Not a single complete life-history of any of these prawns is known, and there is here a great opportunity for research which should yield good results. Methods of fishing and curing are mostly very primitive although in certain parts, notably Madras, much progress has been made in improving methods, gear and boats. More research is necessary in every direction, and Dr. Chopra's address indicates the special needs of the industry.

Age Determination and Rate of Growth in Polyodon spathula, by Means of the Growth Rings of the Otoliths and Dentary Bone

In recent years, papers have appeared on various phases of the life history of Polyodon, but little has been reported on anything pertaining to their age. Stockard (1907) made a study of the habits of Polyodon in Louisiana, Mississippi, and Arkansas, while in search of information concerning their spawning habits. He failed to discover their spawning places, however. In his table of measurements, of 15 specimens from 30 to 69 inches, he mentions two specimens with eggs, one 63 inches and one 69 inches in length. Barbour (1911) described a small specimen 35 mm. in length. Danforth (1911) described a 74 mm. specimen. The smallest specimens now known were collected by Thompson (1933) near Grand Tower, Illinois, on the Mississippi River. These seven specimens were seined from a sandbar and were from 17 mm. to 20 mm. in length. Thompson (1934), in his paper on the relative growth of Polyodon, gives some very interesting tables showing the relation of the rostrum to the body in different periods, varying in total length from 17 mm. to 2159 mm.