The male ducts are either one pair or two pairs, which open by a common and complicated efferent terminal apparatus furnished with a protrusible penis.
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.
The efferent ducts are ciliated, and there is a patch of cilia at the point where they communicate with the cavity of each testis.
D, The branchial efferent vessel carrying aerated blood to the auricle, and here interrupting the circlet of gill lamellae.
G, The branchial efferent vessel.
Br.v, Branchial efferent vessel (vein).
A, of Helix; B, of Eolis; a, ova; b, developing spermatozoa; c, common efferent duct.
By the pulsation of the pericardial vesicle (best observed in the larva) the blood is driven into the glomerulus, from which it issues by efferent vessels which effect a junction with the ventral (sub-intestinal) vessel in the trunk.
Ev, efferent vessel passing into ventral vessel (vv).
These notches are known in Anodonta as the afferent and efferent siphonal notches respectively, and correspond to the long tube-like afferent inferior and efferent superior " siphons " formed by the mantle in many other Lamellibranchs (fig.
These processes are hollow, and receive the venous blood from, and return it again aerated into, the hollow axis, in which an afferent and an efferent blood-vessel may be differentiated.
In the filaments of the gill of Protobranchia and many Filibranchia the tubular cavity is divided by a more or less complete fibrous septum into two channels, for an afferent and efferent blood-current.
A, Of Chiton: f.t., fibrous tissue; a.b.v., afferent blood-vessel; e.b.v., efferent blood-vessel; g.l., laterally paired lamellae.
Each is an outgrowth of the body-wall at the side of the body, and consists of an axis containing two main vessels, an afferent and efferent, and bearing on either side a series of transverse plates whose blood-sinuses communicate with the vessels of the axis.
The afferent vessel of the' ctenidium receives blood from the vena cava or principal blood-sinus of the body, the efferent vessel opens into the auricle of its own side.
Each auricle forms the terminal enlargement of the efferent vein of the ctenidium of its own side.
This action, at first sight somewhat obscure, is due to the extreme pupillary contraction which removes the mass of the iris from pressing upon the spaces of Fontana, through which the intraocular fluids normally make a very slow escape from the eye into its efferent lymphatics.
Matter, according to him, impresses the afferent nervous system, this the brain, this the efferent nervous system, while consciousness remains a mere spectator.
The oxygenated blood is carried from each gill by an efferent vessel on the external or pallial side of the axis to another longitudinal vessel which leads to the auricle on each side.
All ultimately emerge as efferent channels.
Every efferent channel, after entrance in the central nervous system, subdivides; of its subdivisions some pass to efferent channels soon, others pass further and further within the cord and brain before they finally reach channels of outlet.
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 gonads, as in other Arthropoda, are hollow saccular organs, the cavity communicating with the efferent ducts.
Various accessory structures may be connected with the efferent ducts in both sexes.