This "vagina" is sometimes of exaggerated size.
In B it is also joined by a paired vagina (kk) and by the "vitello-intestinal duct" (Laurer's canal), f.
The cerci are nearly always joined, and a typical insectan ovipositor with its three pairs of processes is present in connexion with the vagina of the female.
The two ducts continuous with the gonads open by a common vagina on to the exterior behind the male pores.
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.
Usually they open into a median vagina, formed by an ectodermal inpushing and lined with chitin.
The vagina usually opens in front of the eighth abdominal sternite.
Lead salts are applied as lotions in conditions where a sedative astringent effect is desired, as in weeping eczema; in many varieties of chronic ulceration; and as an injection for various inflammatory discharges from the vagina, ear and urethra, the Liquor Plumbi Subacetatis Dilutum being the one employed.
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).
The perchloride, sulphate and pernitrate are strongly astringent; less extensively they are used in chronic discharges from the vagina, rectum and nose, while injected into the rectum they destroy worms.
From this vagina arises a narrow duct leading to the exterior.
In B it is also joined by a paired vagina k, k, and by the " vitello-intestinal duct " (La.urer's canal, f).
In this group, the accessory gonopore is the opening of the "vagina," in contradistinction to the median and atrial opening of the uterus which is a "birth-pore."
C, genital sinus and neighbouring parts (from Sommer); a, ventral sucker; b, cirrus sac; c, genital pore; d, evaginated cirrus sac: e, end of vagina; f, vasa deferentia; g, vesicula seminalis; h, ductus ejaculatorius; i, accessory gland.
The vagina is a dilatable muscular passage, lined with mucous membrane, which leads from the uterus to the external generative organs; its direction is, from the uterus, downward and forward, and its anterior and posterior walls are in contact, so that in a horizontal section it appears as a transverse slit.
Owing to the fact that the neck of the uterus enters the vagina from in front, the anterior wall of that tube is only about 21 in., while the posterior is 31.
The relation of the vagina to the peritoneum is noticed under Coelum and Serous Membranes.
The hymen is a fold of mucous membrane which surrounds the orifice of the vagina and is usually only seen in the virgin.
The glands of Bartholin are two oval bodies about half an inch long, lying on each side of the vagina close to its opening; they represent Cowper's glands in the male, and their ducts open by minute orifices between the hymen and the labia minora.
From the above description it will be seen that all the parts of the male external genital organs are represented in the female, though usually in a less developed condition, and that, owing to the orifice of the vagina, they retain their original bi-lateral form.
Thus to the eye we may use a solution of sulphate of zinc of half a grain to the ounce, while to the ear, urethra or vagina a solution of four to eight grains or even more may be applied.
They are also employed locally as sprays and douches to the nose, throat, vagina and rectum, for catarrhal conditions of the mucous membranes.
The vagina is often partially divided by a membraneous septum or hymen.
The median vagina, spermatheca and ejaculatory duct are, on the other hand, formed by ectodermal inpushings.
The independent opening of the genital ducts and the absence of an ectodermal vagina and ejaculatory duct are remarkable archaic features of these insects, as has been pointed out by J.
In the Cestodes the vagina is present (V); the canal of Laurer (LC) is now vestigial (present in Caryophyllaeus as the posterior vagina).
Thus in ectoparasitic Trematodes, the paired vagina transmits spermatozoa to the egg: and a canal carries off yolk from this point of junction either to the gut for resorption or to the exterior for exudation.
In addition to this, its long axis forms a marked angle with that of the vagina, so that the whole uterus is bent forward or anteverted.
The large sacs which have been termed vagina are suggestive of the large coelomic spermathecae in Eudrilids, a comparison which needs, however, embryological data, not at present forthcoming, for its justification.
In it the hairs are confined to the dorsal middle line and the creeping setae are hooked, of a finer structure than in Chaetosoma, and situated so far forward that the vagina opens amongst them.
Saginata, showing the generative organs: n., nervous system; ex., longitudinal excretory tubes; tr., transverse vessel; g.p., genital papilla; cl., cloaca; c.p., cirrus pouch; v.d., vas deferens; testes; v., vagina; ov.
The vagina of Cestodes is undoubtedly comparable with the so-called " uterus " of Trematodes, but the nature of the Cestode uterus is not so clear.
The single anterior vagina is then comparable with the similarly named duct of ectoparasitic Trematodes, in which group it is either single or double.
The uterus may be double, each division opening by a separate os uteri into a common vagina, as in Leporsdae, Sciuridae, and Hydrochoerus, or two-horned, as in most species.
In the vast majority of winged insects the terminal part of the genital system (vagina and ductus ejaculatorius) is unpaired and ectodermal.
The chief difference between the reproductive organs of the two classes is the presence in Cestodes of a separate vagina and uterus, each of which opens in some families to the exterior by an independent pore.
The lower half is the neck or cervix and is cylindrical; it projects into the anterior wall of the vagina, into the cavity of which it opens by the os uteri externum.