This sac has been already referred to as a coelomoduct.
Levites, Prophet, Sac Rifice).
Reduction in size is due to A, Two vermiform nuclei in the emthe absence of cytoplasm, bryo sac; one approaching the eggwhich is in some cases so nucleus, the other uniting with the 11 ~ ~h ~h upper polar nucleus.
Strasser, " Luft sac ke der Vogel," Morph.
The old town is composed of winding streets and culs-de-sac bordered by old houses in the Flemish style.
In the majority of the Megascolicidae each sac is provided with one or more diverticula, tubular or oval in form, of a slightly different histological character in the lining epithelium, and in them is invariably lodged the sperm.
In Hyperiodrilus the whole spermatheca is thus included in a corresponding sac, which is of great extent.
Sp', Spermathecal sac involving the last.
Thus, in Philaemon pungens (Lambert) it has the form of a large sac, into which open by a single orifice the conjoined oviducts.
In this Annelid later the sac in question joins its fellow, passing beneath the nerve cord exactly as in the leech, and also grows out to reach the exterior.
The sole difference is therefore that in Eudrilus the ovarian sac gives rise to a tube which bifurcates, one branch meeting a corresponding branch of the other ovary of the pair, while the second branch reaches 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 Gastropoda are mainly characterized by a loss of symmetry, produced by torsion of the visceral sac. This torsion may be resolved into two successive movements.
Movement flexure is also produced by the coiling of the visceral sac and shell; primitively the latter was bowl-shaped; but the ventral flexure, which brings together the two extremities of the digestive tube, gives the visceral sac the outline of a more or less acute cone.
Each renal organ is a sac lined with glandular epithelium (ciliated cell, with concretions) communicating with the exterior by its papilla, and by ce, Cerebral ganglia.
Subsequent connected by nerve investigations carried on under the directo the streptoneur tion of the same naturalist have shown ous visceral loop. that the larger as well as the smaller renal sac is in communication with the pericardium.
Below the surface these walls are excavated with blood-vessels, so that the sac is practically a series of blood-vessels covered with renal epithelium, and forming 6 Cephalic tentacle.
12, and forms a large sac on half of the upper surface of the muscular mass of the foot.
The odontophore is powerfully developed; the radular sac is extraordinarily long, lying coiled in a space between the mass of the liver and the muscular foot.
Areas are found on the foot of the embryo Pulmonate Limax and on the yolk-sac (distended foot-surface) of the Cephalopod Loligo.
It is surrounded by a ridge of cells which gradually extends over the visceral sac and secretes the shell.
F, Side view of the same, showing foot, shell-sac (shgl), velum (vr), mouth and anus.
To the left of the ctenidium a pulmonary sac, separated from it by an incomplete septum, am phibious.
Visceral sac and shell coiled in one plane; foot divided transversely into two parts, posterior part bearing an operculum, anterior part forming a fin provided with a sucker.
Visceral sac and shell small in proportion to the rest of the body, which cannot be withdrawn into the shell; foot elongated, fin-shaped, with sucker, but without operculum.
Q, Sac containing nutritive mb, Mantle-skirt.
(From Keferstein.) a, Shell in A, B, C, shell-sac (closed) in D; b, orifice leading into the subpallial chamber (lung).
The remarkable discovery has been made that in deep lakes such Limnaei do not breathe air, but admit water to the lung-sac and live at the bottom.
Granting sac and soc and other privileges and right in the town.
It does not at first appear to be the same with the bulkier plants, such as the ordinary green herbs, shrubs or trees, but a study of their earlier development indicates that they do not at the outset differ in any way from the simple undifferentiated forms. Each commences its existence as a simple naked protoplast, in the embroyo-sac or the archegonium, as the case may be.
As an example of the former it has been shown (Beddard) that a large median sac in Lybiodrilus is at first freely open to the coelom, that it later becomes shut off from the same, that it then acquires an external orifice, and, finally, that it encloses the ovary or ovaries, between which and the exterior a passage is thus effected.
In Heliodrilus the blind extremity of the spermatheca is enclosed in a coelomic sac which is in connexion with the sacs envolving the ovaries and oviducts.
In such other genera of the family as have been examined, the true spermatheca has entirely disappeared, and the sac which contains it in Hyperiodrilus alone remains.
Sperm, spermatheca; sp. o, its external orifice; sp. sac, spermathecal sac; ov, sac containing ovary;.
R.o, egg sac; od, oviduct.
R.o, Egg sac. od, Oviduct.
Into each ovarian sac behind the transverse junction opens a slender tube, which is greatly coiled, and, in its turn, opens into a spherical "spermathecal sac."
A stage exactly comparable to the stage in the leeches, where the ovary is surrounded by a closed sac, has been observed in Eudrilus.
The larger renal sac (remarkably enough, that which is aborted in other FIG.
Shgl, The primitive shell-sac or shell-gland.
L', The ciliated communication of the renal sac with the pericardium.
Outline of part of the renal sac (nephridium) below the surface.
Soon after quitting the uterus it is joined by a long duct leading from a glandular sac, the spermatheca (Rf).
Carmen watched with excitement as the foal's feet could be seen inside a thin sac... first one and then the other.
They often end in a cul-de-sac. The principal street is the rue de la Kasbah, which leads up to the citadel by 497 steps.
1, The renal sac (nephridium).
The lung-sac serves undoubtedly as a hydrostatic apparatus in the aquatic Pulmonata, as well as assisting respiration.
In this duct and sac the spermatophores received in copulation from another snail are lodged.