The stomodaeum lies in the sagittal plane, the funnel and tentacles in the transverse or tentacular plane.
The sub-class Nuda have no tentacles of any kind; they are conical or ovoid, with a capacious stomodaeum like the cavity of a thimble.
The coelenteron exhibits six lobes, two of which Willey identifies with the stomodaeum of other Ctenophora; the other four give rise to a system of anastomosing canals such as are found in Beroe and Polyclad Turbellaria.
The stomodaeum is compressed laterally, and is furnished with two longitudinal grooves, a sulcus and a sulculus.
The elongation of the mouth and stomodaeum confer a bilateral symmetry on the body of the zooid, which is extended to other organs of the body.
Each zooid has six tentacles; the stomodaeum is elongate, but the sulcus and sulculus are very feebly represented.
The fourth pair, having its muscle-banners on the sulcar faces, is developed at the opposite extremity of the stomodaeum in close connexion with the sulculus.
The mouth and stomodaeum form independently of the blastopore.
In such cases the blastopore may entirely close, and both mouth and anus develop as new ingrowths (stomodaeum and proctodaeum), whilst, according to the observations of N.
One end of the blastopore becomes nearly closed, and an ingrowth of ectoderm takes place around it to form the stomodaeum or fore-gut and mouth.
If the embryonic mouth and anus do become the adult mouth and anus, there would appear to be an entire absence of stomodaeum and proctodaeum in Peripatus, unless the buccal cavity represents the stomodaeum.
This bridge assists in forming a thick investment of mesoblast round the stomodaeum (st).
My own impression is that the stomodaeum and proctodaeum have reached their full extension at the present stage, and that both the stomach in the thorax and the intestine in the abdomen are products of the mesenteron.
The stomodaeum has considerably increased in length, and the proctodaeum has become formed as a short, posteriorly directed involution of the epiblast.
The stomodaeum is considerably larger than in the last stage, and is lined by a cuticle; it is a blind tube, the blind end of which is the suctorial pouch of the adult.
The stomodaeum and proctodaeum are invaginations of the epiblast, while the mesenteron is lined by the hypoblast.
The proctodaeum and stomodaeumare both short, especially the former (vide fig.
A stomodaeum (m) is by this time established and is placed well in front of the foremost pair of appendages[211].
The proctodaeum very early opens into the mesenteron, but the stomodaeum remains closed till the differentiation of the mid-gut is nearly completed.
The stomodaeum in the earlier stage is a simple pit, which meets but does not open into the mesenteron.
The stomodaeum grows greatly in length and joins the dorsal part of the archenteron which then becomes the stomach.
The proctodaeum forms the rectum and Malpighian bodies[169], and the stomodaeum the oesophagus and proventriculus.
The stomodaeum is formed by the usual epiblastic invagination, and becomes the mouth and oesophagus.
The mesenteron is at first a closed sack, but is eventually placed in communication with the stomodaeum and the proctodaeum.
The greater part of the blastoderm gives rise to the epiblast, which furnishes the skin, nervous system, tracheal system, and the stomodaeum and proctodaeum.
The evolution of the embryo commences with the formation of a depression on the ventral surface, at the bottom of which the stomodaeum is formed by an invagination.
At a subsequent period there are developed in the oral region of the stomodaeum the radula in a special ventral pit, and the salivary glands--the latter as simple outgrowths.
The mesenteron is at first a closed sack, independent of both stomodaeum and proctodaeum; and in the case of the Bee it so remains even after the close of embryonic life.
Behind the stomodaeum the remainder of the ventral surface grows out as a flattened foot.
From the primary buccal cavity or stomodaeum there grows out the pituitary pit (fig.
It ends anteriorly at the stomodaeum and posteriorly at the point where the solid remnant of the archenteron in the tail was primitively continuous with the branchial sack.
The communication between the stomodaeum and the mesenteron is effected comparatively early (on the 4th day in the chick), while that between the proctodaeum and mesenteron does not take place till very late (15th day in the chick).
The stomodaeum of Petromyzon is surprisingly large, and its size and structure in this type militate against the view of some embryologists that the stomodaeum originated from the coalescence of a pair of branchial pouches.
In some of the Isopods, for example, the stomodaeum and proctodaeum give rise to almost the whole of the alimentary canal with its appendages, except the liver.
I have not myself completely followed its development in Petromyzon, but I have observed a slight diverticulum of the stomodaeum which I believe gives origin to it.
The mouth and the anus are formed as independent in-pushings, the mouth with stomodaeum first, and the short anal proctodaeum much later.
The pharynx orstomodaeum is still small, the foot not yet prominent.
The stomodaeum likewise has not been identified, but was probably a short gullet leading up from the mouth into the enlarged digestive cavity.
No chitinous lining of the stomodaeum or proctodaeum was found, but it is not certain that any of the sections cut either of those regions.
Thus the ectoderm gives rise to the epidermis, to the nervous system, and to the lining of the stomodaeum and proctodaeum, if such parts of the alimentary canal are present.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "stomodaeum" in a variety of sentences. We hope that you will now be able to make sentences using this word.
