Apertures Sentence Examples

This system of channels is in communication with the outer atmosphere through numerous small apertures, known as stomata, which are abundant upon the leaves and young twigs, and gaseous interchange between the plant and the air is by their assistance rendered constant and safe.

This power of varying the area of the apertures by which gases enter the internal reservoirs is not advantageous to the gaseous interchangesindeed it may be directly the reverse.

Most of these extend through narrow apertures foramina pneumatica - into the hollow bones, sometimes, e.g.

It has been asserted (and denied) that the cellular rod which is known as the "Heart-body" (Herzkorper), and is to be found in the dorsal vessel of many Oligochaeta and Polychaeta, is formed of cells which are continuous with the chloragogen cells, thus implying the existence of apertures of communication with the coelom.

A further degree of modification occurs when the male duct takes its origin from the hermaphrodite duct above the external opening, so that there are two distinct apertures, one male and one female, the latter being the original opening.

The Eolid-like Nudibranchs, amongst other specialities of structure, possess (in some cases at any rate) apertures at the apices of the " cerata " or dorsal papillae, which lead from the exterior into the hepatic caeca.

Dorsal papillae with a membranous expansion; male and female apertures at some distance from each other; pelagic. Fiona.

Genital duct always triaulic, and male and female apertures distant from each other.

Visceral mass and shell conical; tentacles atrophied; head expanded; genital apertures contiguous; marine animals, with an aquatic pallial cavity containing secondary branchial laminae.

Visceral mass and shell conical; head flattened; pallial cavity aquatic, but without a branchia; genital apertures separated.

Male and female genital apertures open into a common vestibule, except in Vaginulidae and Oncidiidae.

Anterior tentacles much reduced; male and female apertures contiguous but distinct; shell thin,.

The Dipylon consists of an outer and an inner gate separated by an oblong courtyard and flanked on either side by towers; the gates were themselves double, being each composed of two apertures intended for the incoming and outgoing traffic. An opening in the city wall a little to the south-west, supposed to have been the Sacred Gate (iep t riAn), was in all probability an outlet for the waters of the Eridanus.

Nasal apertures very large, and extending high on the face between the orbits; nasal bones short, elevated, triangular and pointed in front.

The first segment of the mesosoma of Scorpio and Limulus thus remains the first segment, and can be identified as such throughout the Eu-arachnida, carrying as it always does the genital apertures.

The genital apertures are placed in the first somite following the prosoma, excepting where a praegenital somite, usually suppressed, is retained.

The confluence of the regions of the body and the dislocation of apertures from their typical position are results of degeneration.

When, as in the application to rectangular or circular apertures, the form is symmetrical with respect to the axes both of x and y, S = o, and C reduces to C = ff cos px cos gy dx dy,.

The results of the theory of the diffraction patterns due to circular apertures admit of an interesting application to coronas, such as are often seen encircling the sun and moon.

At other parts of the field the effect is the same, in accordance with the principle known as Babinet's, whether the imaginary screen in front of the object-glass is generally transparent but studded with a number of opaque circular disks, or is generally opaque but perforated with corresponding apertures.

If we take a direction such that the light (of given wave-length) from a single aperture vanishes, the evanescence continues even when the whole series of apertures is brought into contemplation.

If we make the extreme suppositions of an infinitely small source and absolutely homogeneous light, there is no escape from the conclusion that the light in a definite direction is arbitrary, that is, dependent upon the chance distribution of apertures.

The light stopped by the opaque parts of the grating, together with that distributed in the central image and lateral spectra, ought to make up the brightness that would be found in the central image, were all the apertures transparent.

The glass in process of fusion is contained in a basin or tank built up of large blocks of fire-clay and is heated by one or more powerful gas flames which enter the upper part of the furnace chamber through suitable apertures or " ports."

Outline of the ventral surface to show the external apertures and nervous system; a, rosette-organ; b, uterine pore; c, terminal sucker; e, vaginal pore; g, male gonopore; n, o, p, nervous system.

In them a ventral surface containing the usually median male and female genital apertures is generally distinguishable from the smooth FIG.

He seems to have been well acquainted with the projection of images of objects through small apertures, and to have been the first to show that the arrival of the image of an object at the concave surface of the common nerve - or the retina - corresponds with the passage of light from an object through an aperture in a darkened place, from which it falls upon a surface facing the aperture.

He has also given methods of measuring the sun's distance by means of images thrown on screens through small apertures.

About the same time Francesco Maurolico, or Maurolycus, the eminent mathematician of Messina, in his Theore y nata de Lumine et Umbra, written in 1521, fully investigated the optical problems connected with vision and the passage of rays of light through small apertures with and without lenses, and made great advances in this direction over his predecessors.

The first to take up the camera obscura after Porta was Kepler, who used it in the old way for solar observations in 1600, and in his Ad Vitellionem Paralipomena (1604) discusses the early problems of the passages of light through small apertures, and the rationale of the simple dark chamber.

The ventral surface is characterized by one or more suckers and apertures.

If ectoparasitic and attached to the skin, apertures or gills, the Trematode adopts more elaborate adhesive organs and undergoes a less complex development than are required for the endoparasitic members of the class.

There is also a postern gate on the north side of the wall, and at its eastern extremity are two apertures in the thickness of the wall.

Un like the molluscs and annelids, however, the cloacal invagination lies outside this region, and the foot is formed by an elongation of the end of the body between the two apertures.

Some of this light also passed through the second hole, and thus he obtained a narrow beam of practically homogeneous light in a fixed direction (the line joining the apertures in the two screens).

A pair of genital apertures, connected by genital ducts with the paired gonads, are found right and left near the nephridial pores, except in a few cases where the genital duct joins that of the renal organ (Spondylus).

When the edges of the mantle ventral to the inhalant orifice are united, an anterior aperture is left for the protrusion of the foot, and thus there are three pallial apertures altogether, and species in this condition are called " Tripora."

In Mytilus the foot is reduced to little more than a tubercle carrying the apertures of these glands.

The gonads always have their own proper external apertures.

Close to the opening of the utriculus the ejaculatory ducts, already mentioned, open into the urethra by very small apertures.

Thus the condition in the Dermaptera is more primitive than in any other Pterygote order except the Ephemeroptera (Mayflies) which are still more generalized, the primitive mesodermal ducts (oviducts and vasa deferentia) opening by paired apertures as in the Crustacea.

In the Norris basin are the Black Growler and the Hurricane, which consist of small apertures through which steam rushes with such tremendous force that it may be heard for miles.

In the true Chitonidae there are generally two apertures on each side, and in two species three or four, another instance of the tendency to metameric repetition in the group. The auricles are connected with one another posteriorly behind the ventricle.

The valves are hydroscopic, responding to increase in the amount of moisture in the atmosphere by closing the apertures.

It is important for telescope objectives, since their apertures are so small as to permit higher orders to be neglected.

The condition for the reproduction of a surface element in the place of a sharply reproduced point - the constant of the sine relation - must also be fulfilled with large apertures for several colours.

A few months after his return, through Germany, to London in 1815, he was induced to take up the question of constructing a miner's safety lamp. Experiments with samples of fire-damp sent from Newcastle soon taught him that "explosive mixtures of mine-damp will not pass through small apertures or tubes"; and in a paper read before the Royal Society on the 9th of November he showed that metallic tubes, being better conductors of heat, were superior to glass ones, and explained that the heat lost by contact with a large cooling surface brought the temperature of the first portions of gas exploded below that required for the firing of the other portions.

Usually the four subgenital cavities are distinct from each other (so-called tetrademnic condition), but in many Rhizostomeae, for example, Crambessa, the subgenital cavities join together under the subumbral floor of the stomach (so-called monodemnic condition) and coalesce to form a so-called subgenital portico placed on the oral side of the stomach, opening by four interradial apertures between the oral arms, that is to say, by the four primitive apertures of the subgenital pits.

Sometimes they are applied, as in the Copepoda, to the limb-bearing and limbless regions of the trunk, while in other cases, as in the Phyllopoda, they denote, respectively, the regions in front of and behind the genital apertures.

In 10 and the arrows indicate the genital apertures.

In addition, some of the appendages in the neighbourhood of the genital apertures may be modified for the purpose of transferring the genital products to the female, as, for instance, the first and second abdominal limbs in the Decapoda.

It is characteristic of the Malacostraca that the position of the genital apertures is constantly different in the two sexes, the female openings being on the sixth, and those of the male on the eighth thoracic somite.

The latter division, characterized by the possession of 19 somites and pairs of appendages (apart from the eyes), by the division of the appendages into two tagmata corresponding to cephalothorax and abdomen, and by the constancy in position of the generative apertures, differing in the two sexes, is unquestionably a natural group. The Entomostraca, however, are certainly a heterogeneous assemblage, defined only by negative characters, and the name is retained only for the sake of convenience, just as it is often useful to speak of a still more heterogeneous and unnatural assemblage of animals as Invertebrata.

The pericardium being absent, there are no reno-pericardial apertures.

Grimaldi (1618-1663) on interference by the employment of apertures for the transmission of the light, and was thus enabled in the most conclusive manner to account for the phenomena of interference in accordance with the undulatory theory.

The genital apertures are placed on the first somite of the second tagma or mesosoma.

The genital apertures are neither far forward nor far backward in the series of somites, e.g.

The genital apertures are median and placed far back in the series of somites, viz.

The Hexapoda are not only all confined to a very definite disposition of the somites, appendages and apertures, as thus indicated, but in other characters also they present the specialization of a narrowly-limited highly-developed order of such a class as the Crustacea rather than a range from lower more generalized to higher more specialized forms such as that group and also the Arachnida present.

Quincke have shown that they depend upon the size and form of the apertures and upon the state of the surface on which they are traced.

The apertures of the tracheal system are placed in the depressions between the papillae or ridges of the skin.

The tracheal apertures are diffused over the surface of the body, but are especially developed in certain regions.

But since no rays are lost in this transmission (apart from the slight loss due to reflection) the brightness of the image point in the water is as large as that in air, although the apertures have become less.

Rohr's monochromats are constructed with apertures up to 1.25.

These two conditions are only compatible when the representation is made with quite narrow pencils, and where the apertures are so small that the sines and tangents are of about the same value.

Very large apertures occur in strong microscope objectives, and hence the two conditions are not compatible.

This refers to systems with small apertures, but still more so to systems with large ones; chromatic aberrations are exceptionally increased by large apertures.

In systems with smaller apertures variations of the thickness of the glass cover are not so noticeable.

Condensers are for this reason also constructed with apertures up to 1 40.

Finally, three standard louvered apertures at the top of the wall.

The paste flowing into the stencil apertures, filling them.

Extended Performance X-ray - similar to the hardwood bolection bead (see Plasform original) for square or rectangular apertures only.

When elementary particles collide at high energies they diffract off each other, just like waves of light diffract around apertures in ordinary optics.

MicroStencil has developed a process which forms high tolerance apertures with extremely smooth sidewalls.

However, above each silo in the west wall are blocked apertures that also contain silicates.

They also provide the solution to the problems of scooping or scavenging that polyurethane squeegees create with larger apertures.

Except in the tower, the 1857 windows are trefoil-headed lights with trefoil tracery above, set in square-headed apertures.

Did I specifically request Magnum P.I. 's chest wig to be crammed into such tiny and personal apertures?

The ventral and lateral parts of the anterior margin of the collar constitute the so-called operculum (op.), a structure which not only acts as a lower lip, but must be important in separating the food-current produced by the cilia of the tentacles from the external apertures of the collar-canals and gill-slits.

The nozzles of small lamps are inserted in the tubes L, L, for illuminating the webs in a dark field; the light from these lamps is admitted through apertures in the strong hollow cylinder above mentioned (for illumination, see p. 385).

The tax on doors and windows is levied in each case according to the number of apertures, and is fixed with refetence to population, the inhabitants of the more populous paying more than those of the less populous communes.

There is thus a broad resemblance to the Eudrilidae, to which group of Oligochaeta the Hirudinea are further akin by reason of the invariably unpaired condition of the generative apertures, and the existence of a copulatory apparatus (both of which characters, however, are present occasionally in other Oligochaeta).

The so-called Grotto of the Cumaean Sibyl, on the south side, is a rock-cut passage, ventilated by vertical apertures, possibly a part of the works connected with the naval harbour.

It is usually most convenient to employ a telescope focused upon the radiant point, and to place the diffracting apertures immediately in front of the object-glass.

If, however, as in practice, the light be heterogeneous, the source of finite area, the obstacles in motion, and the discrimination of different directions imperfect, we are concerned merely with the mean brightness found by varying the arbitrary phase-relations, and this is obtained by simply multiplying the brightness due to a single aperture by the number of apertures (n) (see Interference Of Light, § 4).

Taking as a starting-point the wide archenteric cavity which the medusa inherits primitively from the antecedent actinula-stage (see article Medusa), we find, in such a form as Tessera, four interradial areas of concrescence between the exumbral and subumbral layers of endoderm, four so-called septal nodes or " cathammata," subdividing the stomach into four wide, radially situated pouches which communicate with each other beyond the septal nodes by wide apertures constituting what is termed by courtesy a ring-canal.

The bell turret rises directly from the gable end; two-tiered with a saddleback roof; small apertures with sandstone dressings.

Modern slab floor with a tile surround; exposed masonry with deeply splayed apertures.

The movie feature includes in-camera editing for movie files and the ability to change apertures when recording clips.

When setting up the recessed lighting in a room, you have the option of using stand alone, low voltage task light apertures.

Male and female apertures distant.

Narrow apertures between adjoining galleries.

The position of the genital apertures is not known.

In the same figure the free part of the inner lamella of the inner gill-plate resting on the foot is marked z, whilst the attached parjt - the most anterior - has been snipped with scissors so as to show the genital and nephridial apertures x and y.

Hence, except for the formation of a urino-genital groove, the apertures are placed as they are in Anodonta.

In Mytilus the two apertures are on a common papilla, in other cases the two apertures are as in Anodonta.

The Anatinacea and Poromya among the Septibranchia are, however, peculiar in having two genital apertures on each side, one male and one female.

Renal and genital apertures separate.

Tridacnidae.-Mantle closed to a considerable extent; apertures distant from each other; no siphons; a single adductor; shell thick.

At this time, however, the flesh was replaced by a stuffing of sawdust, sand, or other lasting material, introduced with great skill through a few incisions and apertures, so that the natural forms were completely restored.