For our present knowledge of the power of intracellular digestion possessed by the endoderm cells of the lower invertebrates removes all difficulties both as to the mode of entrance of the algæ, and its fate when dead.
A large share of the substances thus prepared falls down to the bottom of the cavity and are there digested by the endoderm cells.
The walls of the tentacles do not differ in general structure from those of the column, but the cells of the endoderm are smaller and the nematocysts of the ectoderm more numerous, and there are other minor differences.
The colouring matter in its body becomes broken up into irregular patches owing to degeneracy of the endoderm cells, and it dies within a few hours.
The endoderm consists mainly of comparatively large cells with polygonal bases which can be seen from the external surface of the column in colourless individuals.
I have noticed in specimens from Lahore and the neighbourhood that very minute spherical bodies of a dark green colour are present in the endoderm cells.
Digestion is then a much more rapid process, and the excreta contain minute, irregular, coloured granules, which appear to be identical with those contained in the endoderm cells of individuals that have recently digested a meal fully.
The invaginated cells (derived from the division of the four big cells) form the endoderm or arch-enteron; the outer cells are the ectoderm.
Between the Ectoderm and the Endoderm a layer of cells called the Mesoderm or Mesoblast is next formed, and from these three layers all the parts of the embryo are built up.
Lankester, "On the intracellular digestion and endoderm of Limnocodium," Quart.
An endodermal axis is continued through the whole structure, and in one or more of the endoderm cells of the club-shaped body otoliths are always present.
Whether there is any part of it in many types not so derived requires further investigation, now that it has been shewn by the Hertwigs that part of the system develops from the endoderm in some Coelenterata.
The terminal portion of the endoderm is solid, and contains calcareous concretions.
Other cells in the endoderm have long flagellate processes which vibrate back and forth in the digestive cavity, thereby creating currents in the water containing food-particles.
Many of the endoderm as well as ectoderm cells have muscle-processes which spread out from the base of the cell and which serve to contract and expand the body.
The endoderm lines the body-cavity, particles taken in as food being digested by certain digestive cells which thrust out amoeboid processes and ingest particles of food.
In the course of development, however, cells from the ectoderm and endoderm may migrate into it.
In Actinians the epithelio-muscular cells of the endoderm are crowded with yellow spherical bodies, which are unicellular plants or Algae, living symbiotically in the tissues of the zooid.
As the mesenteries are formed, the endodermof the basal disk lying above the basal plate is raised up in the form of radiating folds.
The endoderm contains in addition gland cells and nervous elements.
The inner layer or endoderm is also a cellular layer, and is chiefly made up of columnar cells, each bearing a cilium at its free extremity and terminating internally in a long muscular fibre.
Between the Ectoderm and Endoderm lies an intermediate layer the Mesoderm.
The glandular lining of the alimentary canal corresponds with the endoderm of Hydra; although this, too, is a more complicated affair.
Ec, Ectoderm or skin layer; En, Endoderm or stomach layer; m, mouth leading into the enteric cavity.
Huxley, in describing the development of the Hydrozoa--the endodermand ectoderm.
Coelentera were homologous with the ectoderm and endoderm of the germ was thus fully confirmed and greatly extended.
The origin of the notochord from the endoderm was also not made out by Kowalevsky in his paper of 1867.
The endoderm is generally also an epithelium one cell in thickness, the cells being digestive, secretory and sometimes muscular.
The sexual cells of the medusoid lie in the endoderm on interradii, that is, on the second set of radii accentuated in the course of development.
These free yolk-cells do not take part in the formation of the germinal layers, nor does the endoderm when formed give origin to free yolk-cells.
The endoderm of the spadix of the hydranths is of a rich orange colour, which becomes paler as it descends towards the less highly organized stem.
That portion of the endoderm which forms the boundary of the body-cavity has fewer green corpuscles, but contains irregular brown granules, thus roughly mapping out a structural region.
Small coloured bodies, as in the endodermof hydra, p.
The ectoderm is indicated by close hatching, the endoderm by light hatching, the mesogloea by thick black lines, the horny skeleton of the pneumatophore and sail by dotting.
The endoderm is shaded, the ectoderm is left clear.
Vacuolated Endoderm Cells of cartilaginous consistence from the axis of the tentacle of a Medusa (Cunina).
The endoderm of the polyp is typically a flagellated epithelium of large cells (fig.
The epiblast now with its mesoblastic lining begins to form the Chorion, an embryonic intrauterine appendage; and the endoderm encloses the Archenteron or primitive gut.
The outer is the Ectoderm and the inner is the Endoderm or Hypoblast.
From the endoderm come the epithelium of the respiratory tract, of most of the digestive tract with the liver and pancreas, the epithelium of the thyroid body, the bladder, and other minor parts.
This invaginated layer of cells, brought into a new position with regard to its environment, becomes the endoderm and receives the stimulus to assume the character appropriate to the new environment.
The walls of the endoderm are, in most species, uniform, but, with P.
The leaves differ from all that I have examined in showing thick-walled endoderm cells, but the cone corresponds with many of my own collection.
Such a necessity is explained by the fact that the endoderm consists entirely of germ-cells.
Now the life of the organism, being dependent upon the mutual action of both layers, must cease as soon as the whole endoderm is extruded during reproduction.
It is clear, both from their origin and history, that the layers or masses of cells called ectoderm, endoderm and mesoderm have not the same value in different animals; indeed, it is misleading to speak of three layers.
In yet others it is partly derived from endoderm and partly from ectoderm (primitive streak of amniotic Vertebrates).
Huxley, who compared the serous and mucous layers of Pander with the ectoderm and endoderm of the Coelenterata.
The part played by the ectoderm and endoderm appeared quite clear, and the former might reasonably be regarded as the cutaneous investment of primitive multicellular animals, while the latter might be regarded as their organ of digestion.
He found that in certain inferior sponges the mesoderm develops before the endoderm and gives birth to it.
Metchnikoff gave to that stage the name of parenchymella, for the migrating cells constitute the endoderm in the condition of a parenchyma.
It has usually been regarded as representing both endoderm and mesoderm, and the groove which usually leads to its formation has been compared to the abnormally elongated blastopore of a typical gastrula.
Mes o gle' a#, a non-cellular layer between ectoderm and endoderm cells.
Mesoglea, a jelly-like layer between the endoderm and ectoderm layers.
What are at least two of the functions of the endoderm cells?
In sponges it is believed that endoderm and ectoderm cells are able to exchange positions and functions.
Identify the endoderm and ectoderm cells, the spicules or fibers, and, among the spicules or fibers, irregular amoeboid cells, sometimes called mesoderm cells.
A depression appears at the point where the blastoderm closed and internally the pro-endoderm or inner layer is differentiated into two--the endoderm proper and the mesoderm (see fig.
Entoderm: the innermost germ layer of the embryo, from which are derived the epithelium of the alimentary canal and accessory structures: = endoderm and hypoblast.
Endomesoderm: the inner layer formed by an invagination of the middle portion of the primitive band of the embryo, and from which the endoderm and mesoderm are subsequently differentiated.
The formation of the germ layers may go on in a different order and under very different conditions: a rather close relative of our Echinus, for instance, the starfish, forms first the endoderm and afterwards the mesenchyme.
We first repeated Chun’s experiment and obtained his results, with the sole exception that there was a tendency of the endoderm of the half-larva of Beroë to become more than “half.
And so we may summarise both our last results by saying: though ectoderm and endoderm have their potencies equally distributed amongst their respective cells, they possess different potencies compared one with the other.
We propose to call these “elementary morphogenetic processes”; the turning in of the endoderm and its division into three typical parts are examples of them.
But the diversity of the endoderm with respect to the ectoderm is not of the same kind as its diversity in respect to the blastoderm.
By another sort of experiment, which we cannot fully explain here, it has been shown that the endoderm if isolated is also only able to form such organs as are normally derived from it.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "endoderm" in a variety of sentences. We hope that you will now be able to make sentences using this word.
