Wing Width Research Articles

The gametophyte of some Jamaican thelypteroid ferns

A study of the development of the gametophyte of 16 thelypteroid ferns from Jamaica reveals similarities and some differences among them which may have some bearing on their taxonomic position. They all possess a hairy, relatively long-lived thallus which at maturity is cordate, relatively delicate for its size, with a wide cushion, broad wings, abundant colourless or pale tan rhizoids and sex organs of the advanced type. Although spore ornamentation, length of gametophytic simple hair and form and dehiscence of the antheridium are features which differ among the species, two gametophytic characteristics set apart the goniopteroid representatives: a branched hair and the development of the cell plate from subterminal cells of the germination filament when the filament ends in a hair. The presence of these with other minor and inconsistent differences suggests a not very close relationship of Goniopteris with Meniscium and supports those authors who prefer generic distinction.

Automated Spectrophotometry

Starting from a digitized and calibrated stellar spectrum—what can we most usefully do with it?Traditionally a spectrum consists of two parts, a continuum and some lines. These have been variously defined in the past, so perhaps another definition may be allowed. Over large ranges the two components can be distinguished quite sharply in the spatial frequency plane. The continuum contains only low frequencies, whereas in the line the information is contained in the high frequencies. In the word “continuum” is included the instrumental absorption functions, emulsion sensitivity, wide interstellar and atmospheric bands, and even the wide wings of very strong lines. From the word “lines”, on the other hand, the strongest lines are excluded; these may contain intermediate spatial frequencies in their core regions. They are relatively infrequent and so may be treated as special cases.

Clines in body dimensions in populations of Drosophilia subobscura

Five dimensions—wing length and width, thorax length, head width and tibia length—have been measured on samples of twelve populations of Drosophila subobscura taken from different parts of the species range, extending from Scotland to Israel. The populations had been started from thirty or more pairs of flies and maintained in the laboratory for eight to eleven generations. They were reared for measurement under standard conditions, so that any differences between them must be of genetic origin. The localities from which the populations came ranged over 25° of latitude and 15° F. in mean annual temperature.The population means of the five dimensions all showed strong positive correlations with latitude and slightly lower negative correlations with mean annual temperature. There is, in consequence, a very uniform cline in the five dimensions, each increasing as we move northwards. This pattern differs from that found for essentially the same dimensions of D. robusta by Stalker & Carson (1947), where all the correlations with latitude are lower and those for head and thorax size are of opposite sign in the two species.A partial correlation analysis and reference to selection experiments suggests that there are two distinct groups of genes involved in these clines: (1) a group of genes causing increase in relative wing and leg size, and responsible for the positive correlation of these dimensions with latitude in both species, and (2) a group of general size genes causing correlated changes in all dimensions, which have been selected in opposite directions in the two species, with the result that head and thorax size increase in subobscura but decrease in robusta as latitude increases. The ratio of wing length to thorax length has a high positive correlation with latitude in both species.Further analysis of the data available on both species brings out the following points:1. In subobscura there is considerable variation between localities remaining for all dimensions when the correlations with latitude are eliminated. This component of variance is much larger in proportion to the within-locality variance in subobscura than in robusta.2. Comparison of the percentage regression coefficients of dimensions on latitude or temperature shows that individual dimensions change more rapidly in proportion to both geographical indices in subobscura, but the ratio of wing to thorax length ?changes more rapidly in robusta.3. The ‘environmental’ regression of dimension on temperature of rearing in the laboratory, measured only for robusta, is very much higher than the corresponding genetic regression between populations on mean annual temperature for all the robusta dimensions and different in sign for head and thorax size. But this environ mental regression is uniformly only about twice as high as the corresponding genetic regression for each character in subobscura. Unexpectedly, the environmental and genetic regressions on temperature of the wing/thorax length ratio are equal in robusta.4. D. subobscura is about 20% smaller in head and thorax size, and 26% less in wing width, than robusta, when both species are reared at 18° C.5. The basic within-culture variances of the five dimensions are 50–100% greater in subobscura than in robusta for all dimensions. Variability in D. melanogaster is about the same as in D. robusta.Some of the possible implications of these results are discussed.

Heterosis in the Honey Bee as Shown by Morphological Characters in Inbred and Hybrid Bees

Inbred queens from eight lines representing several races of honey bees (Apis mellifera L.) were mated (artificially inseminated) to drones of the same line and also to another line, so that inbred and hybrid worker offspring were produced simultaneously from each mother queen. By the use of genetic markers the two types of offspring were identifiable. Small but highly significant differences between lines were found in the characteristics length, wing width, cubital index, number of wing hooks, tongue length, and antenna lengths. The hybrid bees were usually larger than their inbred sisters. This difference in size suggests that hybrid vigor is present in honey bees. Uncontrollable feeding variability between colonies apparently accounted for significant differences in some samples.

Spectrophotometry of WoIf-Rayet binary systems.

view Abstract Citations (8) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Spectrophotometry of WoIf-Rayet binary systems. Bappu, M. K. Vainu ; Sinvhal, S. D. Abstract Spectra obtained at the cassegrain focus of the Mt. Wilson 6o-inch telescope over two seasons of observing have been used to study the variation of emission line intensities and the profiles of a few Wolf-Rayet binary systems. The binaries chosen are HD 214419, HD 193576 and HD 193928 having periods of 1.64, 4.21 and 21.64 days, respectively. Of these three, only two have been known to be eclipsing variables. HD 214419. Hiltner (1950) has found by photoelectric methods that the intensity of Heii 4686 in the binary reaches a maximum during conjunctions and~a minimum at elongations. We have measured equivalent widths at different phases for the lines Heii 6560, Hei 5875, Heii 5411 and Niv 4058. The equivalent widths of all these lines have a pattern of behavior identical to that of Heii 4686, in that all of them show increased intensities at primary and secondary minima with a lower value of intensity at elongations. On certain nights the emission intensity is considerably above average as noted by Hiltner. On such occasions, there is corresponding increase in the intensity of the other lines showing that a change in the general overall excitation mechanism is the responsible agent for the fluctuation. There are no very conspicuous changes with phase in the profiles of X4686 as has been noted in the case of HD 193576. Nearly always at the primary minimum when the Wolf-Rayet star is behind its companion, the X4686 profile has a sharp peak at the centre with wide distended wings. At secondary mini- μm when we receive radiation primarily from the Wolf-Rayet star a well rounded profile results with a slight asymmetry on the long wavelength side. The shapes at primary minimum of the profiles of Heii 4686, Heii 6560, Heii 5411 and Niv 4058 resemble the curves that would result, were the profiles outside eclipse modified by electron scattering. There is evidence that the half-widths of Niv 4058 increase at primary minimum. Such a result may be obtained if self-reversal effects are conspicuous at primary minimum, or if the macroscopic motions in the circulatory system of gas around the two components are appreciable. The former alternative may be disregarded since the profiles do not suggest any self-reversal effects. An interesting feature is the development of intense violet edges immediately after the primary and secondary minima. All the Heii lines develop such a violet edge and this pattern is followed by the Hei lines at XX5875 and 4471. It is difficult to observe this effect in the violet wing of ~656o since the io~a-F emulsion used has a dip in sensitivity in this wave-length region. HD 193576. Well-widened spectra in the blue region for this star have been used in the determination of equivalent widths for Heii 4860, Heii 4686, Nv 4603 and Niv 4058. When plotted with phase the lines Heii 4686 and Niv 4058 have negligible eclipse effects at primary minimum. Heii 4860 and Nv 4603 have minimum intensities at primary minimum, in the latter case probably caused by its own intense violet edge coupled with the violet edge of ~46I9 of Nv. HD 193928. Large scale variations in the emission-line intensities of the violet edges of Hei 4471 and Nv 4603 are easily noticeable. At certain phases X4860 as well as Heii 4686 develop humps on the long wave-length side of the profile. In the case of HD 214419 we find that the increase in brightness at primary and secondary minima is shared by all the emission lines measured. In HD 193576, Heii 4860 and Nv 4603 do not share the behavior of Heii 4686 and Nvi 4058. It would be of great interest to obtain photoelectric light curves of this star in the light of Heii 3206 and Niv 3483. One of us (Bappu 1951) has suggested that the increase in intensity of the emission lines in HD 214419 could be explained on the basis of a common envelope model. Such a situation would demand that the abnormal behavior be shared by all the emission lines together, a phenomenon that we have found to exist in HD 214419. The validity of the common-envelope hypothesis would cease to exist in those systems that are not close binaries. Verification of this hypothesis might therefore be made by carrying out programs of emission line photometry in WolfRayet binary systems having different periods. Bappu, M. K. V. 1951, Harvard thesis. Hiltner, W. A. 1950, Ap. J. 112, 447. U. P. Government Astronomical Observatory, Banaras, India. Publication: The Astronomical Journal Pub Date: June 1955 DOI: 10.1086/107182 Bibcode: 1955AJ.....60..152B full text sources ADS | data products SIMBAD (3)

Methods for Calculating the Flow in the Trefftz-Plane Behind Supersonic Wings

By means of the linearized nonviscous theory, methods are developed, using the complex functions of conical flow, for finding downwash and sidewash in the Trefftz-plane—i.e., a t an infinite distance downstream, behind a supersonic wing. Equations are derived which describe this flow field behind several types of flat plate wings: the wide delta wing, the trapezoidal wing (wide delta wing with cutoff tips), and the delta control surfaces (a narrow delta wing, the two sides of which are deflected differentially). Graphs are included which show the results for these cases.

The Hydrogen Line Widths in 5 κ Draconis

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Hydrogen Line Widths in 5 κ Draconis van Arnam, Ralph N. Abstract Contours of H13, H7, and H~ from twelve spectrograms of 5 K Draconis, in which double emission components are superposed on the absorption contour of Hj3, fail to show correlation between intensity of emission and width of absorption wings. This is taken as added evidence in support of the hypothesis that these lines originate at differ- ent levels in the star Publication: The Astrophysical Journal Pub Date: January 1934 DOI: 10.1086/143523 Bibcode: 1934ApJ....79..140V full text sources ADS |

TWO NEW SPECIES OF CIXIUS (HOMOPTERA, FULGORIDAE)

Length, apex of head to tips of wings 5.75 mm.; width of wing at apex of clavus 1.75 mm.Vertex broad, transverse, resembling pini, median length distinctly less than half as great as width at middle of posterior margin; anterior margin very broadly arcuate, posterior margin scarcely less so. Frons almost twice as long at middle as is clypeus, slightly transversely elevated just before lower margin; greatest width equal to median length. Pronotum with posterior margin slightly obtusely angulate at middle. Mesonotum tricarinate, median carina well defined anteriorly but obsolescent at apex, lateral carinae entire, distinctly divergent posteriorly.

AN INSTRUMENT TO DETERMINE THE DIFFERENCE IN EXPANSION OF THE TWO SIDES OF THE UPPER CHEST IN PULMONARY TUBERCULOSIS

This instrument, which I have called "thora-meter," is built after the plan of the original caliper, with special features attached to the free ends. The arms of the caliper are curved slightly, with ends curved to point at right angles with the length of the arm. One arm is longer than the other, and has attached a pad of the ball and socket type, permitting free movement and conformity to the surface of the body. The other and shorter arm of the caliper has attached a measuring device, composed of a barrel with a movable rod passing through, controlled by a coil spring. This plunger rod passing through the barrel is calibrated for measuring expansion, and is held snugly against the surface by the coil spring, which permits free movement of the plunger during respiration. The caliper joint is made of wide wings with a thumb nut to hold the

New Miscellaneous Chalcidoid Hymenoptera with Notes on Described Species.

Ovipositor half the length of the abdomen, white tipped. Dark metallic green, the following parts silvery white: Vertex, scape except bulb and middle, apical half of the pedicel, funicles 2 and 4, trochanters, knees, tips of tibiæ and middle three joints of the tarsi. Venation dusky, base of marginal vein and the stigmal vein pale. Fore wings with a distinct, oblique (caudo-distad), sooty cross-stripe from the distal two-thirds of the marginal vein and the side of the stigmal. Marginal fringes of the fore wing short, the longest not an eighth of the greatest wing width. Pedicel somewhat longer than wide, barely shorter than funicle 1 which is over twice longer than wide; funicle 2 thrice longer than wide and longest, 4 slightly shorter than 2, 3 slightly longer than wide. Club longer than the two preceding joints combined. Mandibles tridentate.

NEW SPECIES OF NORTH AMERICAN MYRMELEONIDAE

In the Canadian Entomologist for March, 1899, page 70, Mr. Nathan Banks describes a new species of Brachynemurus under the name tuberculatus. The specimen used in drawing up the description was a female, and as I find a male of this species in the National Museum collection, a description of it is given here:Brachynemurus tuberculatus, Banks.Male.—Length, 21.5 mm.; expanse of wings, 33 mm.; greatest width of anterior wing, 3.6 mm.; length of antennae, 4 mm. Much smaller and more slender than the famale.

NEW SPECIES OF NORTH AMERICAN MYRMELIONIDÆ

Brachynemurus brunneus, new species.Male.—Length, 40 mm.; expanse of wings, 55.4 mm.; greatest width of anterior wing, 6.4 mm.; length of antenna, 7 mm. Slender, prevailing colour fuscous, markings luteous; sparsely clothed with black and white hairs, more thickly so on abdomen.Face scarcely convex; lower part luteous; covered above by a broad piceous band which encircles the antennæ furrow between face and inner orbit of the eye fuscous. Circumocular area luteous, except along vertex, where it is mostly dark fuscous, and near the maxillary palpiger, where there is a fuscous spot. Clypeus luteous, rather short. Labrum transverse, luteous; rounded laterally and narrowed anteriorly emarginate in front. Mandibles piceous, black at tips.

NEW SPECIES OF NORTH AMERICAN MYRMELIONIDAE

Brachynemurus Hubbardii, new species.Male–Length, 46 mm.; expanse of wings, 49.5 mm.; greatest width of anterior wing, 6 mm.; length of antenna, 9 mm. Very slender; yellow, marked with dark fuscous; sparsely hairy, more thickly on abdomen.Face scarcely convex, yellowish; above, a broad pitchy-black band, notched in middle below, extending around the antennae on outer side; a faint fuscous line extends from centre of notch almost to clypeus; furrow between face and inner orbit of the eye, fuscous. Circumocular area yellowish, except along depressed portion of the vertex, where it is dark fuscous, and below, near maxillary palpiger, where there is a black spot. Clypeus yellowish, with a few coarse black hairs. Labrum transverse rounded laterally and narrowed anteriorly somewhat emarginate in front, yellowish, slightly tinged with rufous, several coarse dark hairs on anterior border. Mandibles piceous, black at tips; on inner edge, near apex, a tooth.

NEW SPECIES OF NORTH AMERICAN MYRMELIONIDAE.–II.

Brachynemurus niger, new species.Female.—Length, 29 mm.; expanse of wings, 56mm.; greatest width of anterior wing, 7 mm.; length of antenna, 4 mm. Black, marked on head and thorax with luteous; sparsely hairy, more distinctly so on prothorax and abdomen.Face scarcely convex, luteous, a transverse, shining black band above which extends upward so as to cover the inter-antennal area; this band is notched below, a black line extending form the notch almost to the clypeus; on either side between face, clypeus and inner orbit of the eye, a triangular black dot. Circumocular area mostly luteous, except along vertex, where it is piceous. Clypeus luteous, on each side anteriorly an impressed dot. Labrum transverse, rounded laterally, emarginate in front, luteous, darker on emargination where it is sparsely clothed with black hairs. Mandibles piceous, black at tips.

NEW SPECIES OF NORTH AMERICAN MYRMELIONIDAE.–I

Brachynemurus Coquilletti, new species.Male.—Length, 33 mm.; expanse of wings, 44 mm.; greatest width of anterior wing, 5.6 mm.; length of antenna, 6 mm.; luteous, marked with dark fuscous; clothed with white hairs, thickly so on abdomen; apical segments of abdomen with some black hairs among the white ones.Face flat, luteous, bordered above by a pitchy-black band separating the antennae and narrowly bordering them in front and on the outer side; a longitudinal median black line extends from this band almost to the clypeus. Circum-ocular area luteous, except along the anterior portion of the vertex, where it is fuscous, and on the margin next the eye, opposite the middle of anterior joint of maxillary palpiger, where there is a fuscous spot. Clypeus rather short, luteous, on either side anteriorly an impressed spot; above, a few black bristles. Labrum transverse, luteous; rounded laterally and narrowed anteriorly, nearly straight in front, where it is sparsely clothed with light-coloured hairs. Mandibles piceous, black at tips.