Duct Sentence Examples

On the other hand, the ejaculatory duct with its verticillate sac in the male of Cypris and other genera is a feature scarcely less remarkable.

Into this also opens the genital duct from the single or paired gonad (ov).

The right and left hepatic ducts, while still in the transverse fissure, unite into a single duct which joins the cystic duct from the gall bladder at an acute angle.

It is known the duct of Gartner, and.

Inasmuch as the stone is blocking the duct, the bile is unable to flow into the intestine; so, being absorbed by the blood-vessels, it gives rise to jaundice.

The genital duct opens by a pore into the urino-genital groove of the oyster (the same arrangement being repeated on each side of the body) close to but distinct from the aperture of the nephridial canal.

Solenomya, in which the gonad opens into the reno-pericardial duct.

These forms are hermaphrodite, with an ovary and testis completely separate from each other on each side of the body, each having its own duct and aperture.

In the Scaphopoda there is no distinct genital duct, the relations are as in Aspidobranchia.

It is frequently armed with spines, hooks or stylets, and is further complicated by the addition of a nutritive secretion (the prostate gland) which may open at its base or pass separately by a special duct to the exterior.

The spermatozoa enter it and pass through its walls and traverse a minute duct formed of two accessory cells, and finally enter the ripe ovum.

In the same and other leading forms a pair of much-coiled glandular tubes, the coxal glands (coelomocoels in origin), is found with a duct opening on the coxa of the fifth pair of appendages of the prosoma.

But, on the ground of their air-bladder being closed, or deprived of a pneumatic duct communicating with the digestive canal, such as is characteristic of the Malacopterygians, they were removed from them and placed with the flat-fishes, or Pleuronectidae, in a suborder Anacanthini, regarded as intermediate in position between the Acanthopterygians, or spiny-finned fishes, and the Malacopterygians.

In diabetes this organ seems to play a part which is not yet precisely determined; and one fell disease at least has been traced to a violent access of inflammation of this organ, caused perhaps by entry of foreign matters into its duct.

Tnis duct (Laurer's canal) is sometimes rudimentary and ends blindly beneath the skin.

In the endoparasitic trematodes the uterus is the only passage by which fertilization can be effected, and in cases of cross and selfimpregnation this duct is physiologically a vagina.

The ovary (a) leads into (bb) the oviduct, which is joined at (g) by the duct of the yolk-glands (h).

A, Dorsal view showing the nervous system and digestive system; a, mouth; b, pharynx; c, d, e, gut; E, post-genital union of two limbs of gut; f, excretory pore; g, vaginal pore; h, j, k, brain and nerves; 1, dorsal nerves; m, ventral nerves; n, adoral sucker; o, posterior sucker; p, hooks on posterior sucker; r, vitello-intestinal duct.

Among the Gastropoda, in the Aspidobranchia, there is no genital duct, and the gonad opens into the right kidney; in the more modified forms the left kidney alone is functional, the right has been converted into the genital duct.

Meinert, open to the exterior by a median aperture, the terminal part of the duct being single, either by the fusion of the primitive paired ducts or by the suppression of one of them.

On this view then the Aplacophora are more primitive than the Polyplacophora in the relations of coelom, gonad and coelomoducts; and the genital ducts of the Chitons have arisen either by metameric repetition within the group, or by the gradual loss of an original connexion between the generative sac and the renal tube, as in Lamellibranchs and Gastropods, the generative sac acquiring a separate duct and opening to the exterior on each side.

In the skull there are two orifices to the lachrymal duct, situated on or inside the rim of the orbit.

A curious duct with lateral branches termed the supra-intestinal organ lies above the intestine in the female.

All the cavities of a side are ultimately in communication with an efferent duct opening on the surface of the body a little above the line of attachment of the gills.

The ova are fertilized in the genital duct, and before their escape have undergone the earliest stages of segmentation.

There is a more or less convoluted tube with glandular walls connected internally with a closed " endsac " and opening to the exterior by means of a thin-walled duct.

The external duct of this gland is often dilated into a bladder, and may sometimes send out diverticula, forming a complex system of sinuses ramifying through the body.

The gonad, whose position has already been mentioned, is divided into transverse lobes; its duct is anterior and single, and diverges to the right to open into the right kidney as in primitive Gastropods and Lamellibranchs.

The first member of the series is 3; the second is the product of n 1 two numbers, each equal to 3; the third is the pron e duct of three numbers, each equal to 3; and so on.

Which of the coelomic cavities this last is connected with is uncertain, for there is considerable doubt as to the origin of the genital glands in the embryonic development of recent echinoderms. It seems clear, however, that there was but a single duct and a single bunch of reproductive cells, as in the holothurians, though perhaps bifurcate, as in some of those animals.

Since this must have, on our theory, enclosed the parietal canal from the anterior coelom, it is possible that the genital products were developed from the lining cells of that cavity, and that the genital pore was nothing but its original pore not yet united with that from the water-sac. The concrescence of these pores can be traced in other cystids; but as the genital organs became affected by radial symmetry the original function of the duct was lost, and the reproductive elements escaped to the exterior in another way.

Its duct leaves the inferior anterior angle, at first descends a little, and runs forward under cover of the rounded inferior border of the lower jaw, then curves up along the anterior margin of the masseter muscle, becoming superficial, pierces the buccinator, and enters the mouth by a simple aperture opposite the middle of the crown of the third premolar tooth.

There is no gallbladder, and the biliary duct enters the duodenum about 6 in.

The principal duct enters the duodenum with the bileduct, and there is often a second small duct opening separately.

The nephridia of the first three pairs of legs are smaller than the rest, consisting only of a vesicle and duct.

In all the species except the African species there is a globular receptaculum seminis opening by two short ducts close together into the oviduct, and in the neotropical species there is in addition a small receptaculum ovorum, with extremely thin walls, opening into the oviduct by a short duct just in front of the receptaculum seminis.

Besides the other spaces are definite rounded or oval vacuoles with a permanent pellicular wall termed by Schutt " pusules "; these open by a duct or ducts into the longitudinal groove.

In most male batrachians the testes are drained by transverse canals which open into a longitudinal duct, which also receives the canals of the kidneys, so that this common duct conveys both sperma and urine.

In some of the discoglossid frogs, however, the seminal duct is quite independent of the kidney, which has its own canal, or true ureter.

The sphincter of Oddi surrounds the ampulla and prevents reflux of duodenal contents into the pancreatic duct.

The stent clears a passage through the bile duct to allow the bile duct to allow the bile to drain away.

The thyroglossal duct extends from the foramen caecum, in the floor of the mouth, to the hyoid bone.

For this reason, we prefer to tie the cystic duct using a catgut Roeder external slip knot.

Our results indicate that DNA ploidy is an important, prognostic factor of carcinoma of the hepatic duct confluence.

Dust - duct entries are cut out using a standard hole saw mounted on a cordless drill.

Both gas and electric clothes dryers work by heating air that is blown through a duct into a.. .

The surgery may involve measures to improve drainage of the pancreatic duct, partial or complete removal of the pancreas.

This is joined by the cystic duct from the gall bladder, which then forms the common bile duct.

The Liver and Biliary Tract The biliary tract contains the right and left hepatic ducts, which meet to form the common hepatic duct.

The stent clears a passage through the bile duct to allow the bile to drain away.

The forward section is built around the engine air inlet duct; the aft section is built around the engine.

They are spaced at intervals around the perimeter of the engine exhaust duct near the turbine exit.

The common bile duct then empties into a part of the small intestine called the duodenum.

The examination may be used to locate, and in some cases remove, gallstones stuck in the bile duct.

It grows caudally as a tubular duct which eventually divides to form the isthmus and lobes.

Main air duct pressures were monitored using a water gage manometer.

The nasolacrimal duct connects the inferior end of the lacrimal sac to the inferior meatus of the nose.

Once the heated air leaves the turbines it passes into a bifurcated duct which has a further pair of lateral vectoring nozzles.

This is the third case reported of a patient with persistent mullerian duct syndrome and bilateral seminoma.

Air handling STB and STE units are provided as standard with a duct spigot outlet for connection to ductwork.

Put duct tape on all exposed pipes to prevent anything from getting into them.

Ambient and main air duct temperatures were constantly logged using thermistors and a data logger.

There is also a duct from each kidney called the ureter, which carries urine to the bladder.

The gall-bladder, appropriately designated as "the bitter," was regarded as a part of the liver, and the cystic duct (compared, apparently, to a "penis") to which it is joined, as well as the hepatic duct (pictured as an "outlet") and the ductus choleductus (described as a "yoke"), all had their special designations.

Benham, the tube, though smaller, and with a but little pronounced funnel, has still an intercellular duct.

The network is, however, of the duct of the nephridium, possibly ectodermic in origin, and does not affect the glandular tubes which remain undivided and with one coelomic funnel each.

To the right of the head is seen the muscular penis p, close to the termination of the vas deferens (spermatic duct) vd.

In the most primitive condition the genital duct is single throughout its length and has a single external aperture; it is therefore said to be monaulic. The hermaphrodite aperture is on the right side near the opening of the pallial cavity, and a ciliated groove conducts the spermatozoa to the penis, which is situated more anteriorly.

In front of the osphradium is the single genital pore, the aperture of the common or hermaphrodite duct.

A, of Helix; B, of Eolis; a, ova; b, developing spermatozoa; c, common efferent duct.

Shell external, globular or ovoid; foot elongated, parapodia separate from ventral surface; genital duct diaulic. Lobiger.

Genital duct monaulic; hermaphrodite duct connected with penis by a ciliated groove.

In other species of Helix a second duct (as large in Helix aspersa as the chief one) is given off from the spermathecal duct, and in the natural state is closely adherent to the wall of the uterus.

But in rare cases in Helix aspersa a second spermatheca is found at the end of this second duct.

Tracing the widening female duct onwards we now come to the openings of the digitate accessory glands d, d, which probably assist in the formation of the egg-capsule.

Terrestrial and usually littoral; genital duct monaulic, the penis being connected with the aperture by an open or closed groove; shell with a prominent spire, the internal partitions often absorbed and the aperture denticulated.

The salivary duct opens on its hinder surface.

Anteriorly their vasa deferentia soon unite into a common duct, which opens into the pouch containing the penes.

Its chemical composition - containing, as it invariably does, one or more forms of a complex compound of carbon, hydrogen, pro- oxygen and nitrogen, the so-called protein or albumin The perties of (which has never yet been obtained except as a pro living duct of living bodies), united with a large proportion matter.

It has been compared with the canal of Laurer of Trematodes (the vitello-intestinal duct of the ectoparasitic flukes), but if we take the more primitive Cestodes, and especially Aniphilina, into consideration we find that they possess, in addition to the uterus, an anterior vagina (usually present in Cestodes) and a posterior one.

The single anterior vagina is then comparable with the similarly named duct of ectoparasitic Trematodes, in which group it is either single or double.

In B it is also joined by a paired vagina k, k, and by the " vitello-intestinal duct " (La.urer's canal, f).

A, a segment of Bothriocephalus latus, showing the generative organs from the ventral surface; ex., excretory vessels; c., cirrus; c.p., cirrus pouch; v.d., vas deferens; v.o., vaginal opening; v., vagina; sh.g., shell-gland; od., oviduct; ov., ovary; y.g., yolk-gland; y.d., its duct; ut., uterus; u.o., uterine opening; the testes are not visible from this side; X 23 (from Sommer and Landois).

B, anterior portion more highly magnified (from Marshall and Hurst, after Sommer); cs, cirrus sac; d, ductus ejaculatorius; f, female aperture; o, ovary; od, oviduct; p, penis; s, shell-gland; t, anterior testis; u, uterus; va, vp, vasa deferentia; us, vesicula seminalis; y, yolk-gland; yd, its duct.

In B it is also joined by a paired vagina (kk) and by the "vitello-intestinal duct" (Laurer's canal), f.

A duct leads to the furrow or canal of the tooth.

Stones in the gall-bladder should be removed by operation, as, if left, there is a great risk of their trying to escape with the bile into the intestine and thus causing a blockage of the common bile-duct, and perhaps a fatal leakage of bile into the peritoneum through a perforating ulcer of the duct.

Next in constancy are the " sublingual," closely associated with the last-named, at all events in the locality in which the secretion is poured out; and the " zygomatic," found only in some mammals in the cheek, just under cover of the anterior part of the zygomatic arch, the duct entering the mouth-cavity near that of the parotid.

The duct which runs along its upper and internal border passes forwards in the usual course, lying in the inner side of the sublingual gland, to open on the outer surface of a distinct papilla, situated on the floor of the mouth, half an inch from the middle line, and midway between the lower incisor teeth and the attachment of the fraenum linguae.

Fume Exhaust System RDM Ovens incorporate a powerful and positive, fan assisted, fume and solvent evaporation and exhaust duct system as standard.

There are many factors, which influence the performance of a duct sorbent injection process.

They can be sealed using lapped sections of underlay laid up the face of the duct.

In the room where there is a ventilation duct, shoot the duct.

If you would like to highlight for a wide-eyed, awake look, choose one that is a shade lighter than your skin tone and apply it to the brow bone and tear duct area.

This should be applied first to your inner tear duct using a slightly smaller brush then you used to put on the other eyeshadow colors.

Using the brush, apply the color to the inner tear duct and then blend or pull the color outward toward the outer corner of the eye.Next, you apply your favorite mascara.

On the lower lid, only apply pencil liner to the outer three quarters of the rim, allowing the color to fade as you work your way in to the tear duct.

After reading about someone making a duct tape dress, she decided to go even bigger and try a gum wrapper prom dress.

Split up the players into individual teams or teams of two and give each team a roll of toilet paper and a roll of duct tape.

If you have exposed cords, keetry taping them down with duct tape.

For added energy efficiency, use a caulking gun to close up additional spaces around duct work and pipes and in nail holes.

Butt each sheet together without overlapping and then tape the seams together using duct tape.

If you've recently inquired about the price of professional air duct cleaning, you're probably wondering "can I clean my air ducts myself?"

If moisture affects an air duct system, mold spores or fungus can develop and affect the health of the home's residents.

Professional air duct cleaning services charge at least $400, depending on the size of the house, the cost may exceed $1,000.

The type of brush they use depends on the material of the duct itself.

Air duct cleaning brushes come in different sizes and shapes.

These can be purchased wherever air duct cleaning equipment are sold.

These compressors often work along with mechanical brushes to remove debris from the duct walls.

Vacuum out the air duct with the vacuum's hose.

You won't be able to clean the entire length of the duct this way, but you'll be able to remove a lot of dust and debris.

Before putting the cover back on, clean the air duct register with a household cleaning solution and a rag.

While this way of cleaning air ducts may cut down on the dust that enters your living space, consider renting professional air duct cleaning equipment to thoroughly clean the ductwork.

When choosing a professional air duct cleaning company, ask for references and get at least 3 estimates from different companies.

Ask professional duct cleaning companies about their procedures for protecting the rest of your home from possible contamination during the cleaning process.

One type of UV air sanitizer is installed in the return air duct of a heating or air conditioning system.

Resurrection of Evil offers extremely smooth gameplay and simple mechanics making it relatively easy for anyone to pick up within a short amount of time, although the only improvement they could've added was some duct tape.

Duct tape is also a handy tool for a wide array of situations.

Stent-A slender hollow catheter or rod placed within a vessel or duct to provide support or to keep it open.

These ducts merge into larger and larger channels, like streams flowing into rivers, until they all pour into a single duct that empties into the duodenum (first part of the small intestine).

Between the liver and the duodenum this duct has a side channel connected to the gall bladder.

Infants with a duct obstruction within the liver itself usually require a liver transplant by the age of two.

About 50 percent of bile duct replacement surgeries are successful, and the jaundice usually disappears within several weeks.

It is stored in the gallbladder and passes from the gall-bladder through the common bile duct to the top of the small intestine (duodenum) as needed to digest fat.

Biliary atresia-An obstruction or inflammation of a bile duct that causes bilirubin to back up into the liver.

In CF, thick mucus blocks the pancreatic duct, which is eventually closed off completely by scar tissue formation, leading to a condition known as pancreatic insufficiency.

Pancreatic insufficiency-Reduction or absence of pancreatic secretions into the digestive system due to scarring and blockage of the pancreatic duct.

This duct or shunt normally closes at birth or shortly after.

Each of these has its own separate duct leading to the nipple.

When the ovaries start to secrete estrogen, fat in the connective tissue begins to accumulate causing the breasts to enlarge and the duct system begins to grow.

The breasts and duct system continue to grow and mature with the development of many glands and lobules.

Patent ductus arteriosus is a condition in which the duct that channels blood between two main arteries does not close after the baby is born.

In some cases, a drug called indomethacin can be given to close the duct.

Surgery may be required if the duct does not close on its own as the baby develops.

This can be easily done with two clear one liter bottles, water and duct tape.

Secure the two bottles together with duct tape so that the bottles won't leak.

For this project you'll need a slinky, monofilament line (plastic fishing line), two chairs and masking or duct tape.

The unit offers an optional remote duct kit so the dehumidifier can be located in a different room than the room in need of dehumidification.

Iinstead of the typical Christmas gift baskets, use large gift boxes that are marketed for a distinct "man" vibe to package the creations In fact, you can even tape the package or make a bow using duct tape.

Red boots can be trimmed with white duct tape and sparkling paint can be used to create gold accessories.

You can stick duct tape down an old sweatshirt and carry a boxing glove to be a punch line.

Use duct tape to reinforce the box where needed.

To make the ceremony even more fun, get volunteers from the crowd to make the royal accessories with toilet paper, toilet paper roles, duct tape and cardboard.

Take some duct tape to cover up the razor blade and scrape ashes off of the glass or metal.

Regular duct cleaning can help keep your HVAC unit functioning properly and at maximum efficiency.

When you use the central heating or air conditioning system in your home, the air brought in from outside is filtered and travels through the duct system into the rooms of your home.

If you desire to paint around the duct openings or the grates, now would be the ideal time.

Use the duct tape to secure the hose attachment to the end of the broomstick.

Treat Dad to a one-of-a-kind creation by making a unique duct tape wallet.

You can even personalize the wallet by using colored or patterned duct tape.

Cover the remaining sticky sides with duct tape as needed to create a strip of duct tape "fabric", slightly overlapping the edges.

To make it, you need a wooden kitchen spoon, acrylic paint, a brush, a roll of duct tape and about 12 inches of curling ribbon.

A pimple is nothing more than a plug of fat, skin debris, or keratin stuck in a hair duct.

When the hair duct is closed over, it's classified as a whitehead.

When whiteheads cause the walls of the hair duct to rupture it leads to redness, infection, and pustules, also known as acne or pimples.

The portion of the lachrymal duct communicating with the cavity of the nose has, on the other hand, been abnormally developed, apparently for the purpose of cleansing that chamber from particles of sand which may obtain an entrance while the animal is burrowing.

The lacrymal is always present, and perforated by a glandular duct.

In Lanice conchilega the posterior series of nephridia are connected by a thick longitudinal duct, which seems to be seen in its most reduced form in Owenia, where a duct on each side runs in the epidermis, being in parts a groove, and receives one short tubular nephridium only and occupies only one segment.

There are a clitellum and sperm ducts which though like nephridia have a larger funnel and a less complexly wound duct.

The nephridia are like those of the Oligochaeta in general structure; that is to say, they consist of drain-pipe cells which are placed end to end and are perforated by their duct.

In dextral Gastropods the only structure found on the topographically right side of the rectum is the genital duct.

Passing on, we find not uterine duct.

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

The male duct vd becomes fleshy and muscular near its termination at the genital pore, forming the penis p. Attached to it is a diverticulum fl, in which the spermatozoa which have descended from the ovo-testis are stored and modelled into sperm ropes or spermatophores.

Spermatheca or receptacle of the sperm in copulation, opening into the female duct.

The exterior opening of the duct has been several times alluded to.

These slits are continued into the ciliated duct, being at the same time themselves very strongly ciliated.

When mature, each sac pushes out a process to the exterior, and this forms the genital duct.

Each opens in a vas deferens which bears three diverticula or vesiculae seminales, and three pairs of cement glands also are found which pour their secretions through a duct into the vasa deferentia.

The liver consists of a right and left half, each opening by a broad duct into the stomach.

In 1900 it was shown that the coxal gland of Limulus is provided with a very delicate thin-walled coiled duct which opens, even in the adult condition, by a minute pore on the coxa of the fifth leg (Patten and Hazen, 13A).

His results, so far, have been confirmed by Starling, who finds that the amount of lymph-flow from the thoracic duct is dependent upon difference in pressure.

From the oviduct a long duct full of yolk passes backwards almost to the hinder end of the body and ends blindly in a globular dilatation just below the skin.

This spur, which attains the length of nearly an inch, is traversed by a minute canal, terminating in a fine longitudinal slit near the point, and connected at its base with the duct of a large gland situated at the back part of the thigh.

The poison-fangs are "solenoglyphous," perforated, having a wide hole on the anterior side at the base, in connexion with the duct of the large, paired, poison-glands, the presence of which adds considerably to the characteristic broadness of the head.

The acid gland consists of one, two or more tubes, with a cellular coat of several layers, opening into a reservoir whence the duct leads to the exterior.

The alkaline gland is an irregular tube with a single cellular layer, its duct opening alongside that of the acid reservoir.

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).

The female portion of the duct is more complex.

The Auronectae are peculiar deep-sea forms, little known except from Haeckel's descriptions, in which the large pneumatophore has a peculiar duct, termed the aurophore, placed on its lower side in the midst of a circle of swimming-bells.

In all these cases we have a duct which has a usually wide, always intercellular, lumen, generally, if not always, ciliated, which opens directly into the coelom on the one hand and on to the exterior of the body on the other.

Quite independent of these are certain large dorsally situate funnel-like folds of the coelomic epithelium, ciliated, but of which no duct has been discovered leading to the exterior.

In the former, the duct, leading from the ovarian sac, and swelling along its course into the spherical sac, the "spermatheca," is highly suggestive of the oviduct and receptaculum of the Eudrilidae.

The gonad has no accessory organs and except in Neri- tidae no duct, but discharges into the right kidney.

Poison-gland present whose duct traverses the nerve-collar.

Where these folds cease the common duct splits into two portions, a male and a female.

This paired organ consists of a string of cells which are perforated by a duct opening to the exterior and ending internally in a flame-cell.

The female genital opening usually lies in front of the eighth abdominal segment, the male duct opens on the ninth.

The median vagina, spermatheca and ejaculatory duct are, on the other hand, formed by ectodermal inpushings.

Palmen (1884) on these ducts have shown that in may-flies and in female earwigs the paired mesodermal ducts open directly to the exterior, while in male earwigs there is a single mesodermal duct, due either to the coalescence of the two or to the suppression of one.

The ejaculatory duct which opens on the ninth abdominal sternum in the adult male arises in the tenth abdominal embryonic segment and subsequently moves forward.

A long cystic duct would point to a long reign of the king.

The orifice of invagination forms a pore which may be closed up or may form a protruding duct or funnel.

As regards the inner ear, the endolymphatic duct ends in a closed saccus, imbedded in the dura mater of the cranial cavity.

In Lumbricus the connexion is a little closer; the funnel of the nephridium, in the segments in which the funnels of the gonad ducts are to be developed, persists and is continuous with the gonad duct funnels on their first appearance.

The more complete replacements, such as the nephridia of the genital segment of Tubifex by a subsequently formed genital duct, may be compared with the succession of the nesonephros to the pronephros in vertebrates, and of the metanephros to the mesonephros in the higher vertebrates..

From this vagina arises a narrow duct leading to the exterior.

This fact led Cuvier erroneously to the belief that a duct existed leading from the gonad to this papilla.

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 genital duct is now said to be diaulic, as in Valvata, Oncidiopsis, Actaeon, and Lobiger among the Bullomorpha, in the Pleurobranchidae, in the Nudibranchia, except the Doridomorpha and most of the Elysiomorpha, and in the Pulmonata.

The genital duct is now trifurcated or triaulic, a condition which is confined to certain Nudibranchs, viz.

From the ovo-testis, which lies near the apex of the visceral coil, a common hermaphrodite duct ve proceeds, which receives the duct of the compact white albuminiparous gland, Ed, and then becomes much enlarged, the additional width being due to the development of glandular folds, which are regarded as forming a uterus u.

This second duct has normally no spermathecal gland at its termination, which is simple and blunt.

These posterior brain-lobes, which in all Heteronemertines are in direct continuity of tissue with the upper pair of principal lobes, cease to have this intimate connexion in the Metanemertini; and, although still constituted of (I) a ciliated duct, opening out externally, (2) nervous tissue surrounding it, and (3) histological elements distinctly different from the nervous, and most probably directly derived from the oesophageal outgrowths, they are nevertheless here no longer constantly situated behind the upper brain-lobes and directly connected with them, but are found sometimes behind, sometimes beside and sometimes before the brain-lobes.

Each testis communicates by means of an efferent duct with a common collecting duct of its side of the body, which opens on to the exterior by means of a protrusible penis, and to which is sometimes appended a seminal vesicle.

In this duct and sac the spermatophores received in copulation from another snail are lodged.

In all these cases the female duct bears a bursa copulatrix or receptaculum seminis.

All spiders possess a pair of poison-glands, one in each of the chelicerae or mandibles and opening by means of a duct at the tip of the fang.

Soon after quitting the uterus it is joined by a long duct leading from a glandular sac, the spermatheca (Rf).

The upper, wide opening of the duct is attached by elastic, peritoneal lamellae to the hinder margin of the left lung; the middle portion of the duct is glandular and thick-walled, for the deposition of the albumen; it is connected by a short, constricted " isthmus " (where the shell-membrane is formed) with a dilated " uterus " in which the egg receives its calcareous shell and eventual pigmentation.