In diameter, with little yolk, and the embryos provided with large trophic vesicles (Willey).
Held together by the adhesion of the cell-walls at the surface of Protosiphon and Botrydium, on the one hand, are minute vesicles contact.
A characteristic feature of the more massive species is the occurrence of air-vesicles in their tissues.
In Fucus vesiculosus they arise in lateral pairs; in Ascophyllum they are single and median; in Macrocystis one vesicle arises at the base of each thallus segment; in Sargassum and Halidrys the vesicles arise on special branches.
Other granules, easily mistaken for the " starch " granules, are also found in the cells of Phaeophyceae; these possess a power of movement apart from the protoplasm, and are considered to be vesicles and to contain phloroglucin.
The vesicles of Fucaceae and Laminariaceae prevent the sinking of the bulkier forms. But why certain Fucaceae favour certain zones in the littoral region, why certain epiphytes are confined to certain hosts, why Red and Brown Algae are not better represented in fresh water or Green Algae in salt, - these are problems to which it is difficult to find a ready answer.
The numerous small blisters or vesicles thus derived coalesce, forming a large sac full of "blister-fluid."
From the above-named isopods the present order is strongly differentiated by having heart and breathing organs not in the pleon, but in the peraeon, or middle body, the more or less simple branchial vesicles being attached to some or all of the last six pairs of trunklegs.
A fragment of such a paste brought into a liquid in which the solid particles are soluble, slowly expands into a honeycomb like foam, the walls of the minute vesicles being films of oil, and the contents being the soluble particles dissolved in droplets of the circumambient liquid.
Such a model, properly constructed, that is to say, with the vesicles of the foam microscopic in size, is a marvellous imitation of the appearance of protoplasm, being distinguishable from it only by a greater symmetry.
Io) consist of a pair of testes (te), a pair of seminal vesicles (v), vasa deferentia (v.d.), and accessory glandular tubules (f).
Smith) bears very definite terminal, or intercalary, spherical vesicles, which may probably be regarded as reproductive organs - either oiigonia or sporangia.
Vesica, a bladder), which irritate sufficiently to cause the blood-serum to exude and form vesicles or blisters, e.g.
29); secondly, organs commonly termed otocysts, on account of their resemblance to the audi tory vesicles of higher After 0.
In addition to the stems bearing cups, there are found vesicles associated with them, which have been interpreted as gonothecae or as floats, that is to say, air-bladders, acting as hydrostatic organs for a floating polyp-colony.
Not lobed or indented; tentaculocysts usually enclosed in vesicles; gonads on the radial canals.
The sense-organs are tentaculocysts which are usually enclosed in vesicles and may be sunk far below the surface.
- Margin of the umbrellalobed, tentacles arising from the ex-umbrella at some distance from the margin; tentaculocysts exposed, not enclosed in vesicles; gonads on the sub-umbral floor of the stomach or of the gastric pouches.
These ducts therefore have not their exact counterparts in the Oligochaeta, unless we are to assume that they collectively are represented by the seminal vesicles of earthworms and the vasa deferentia.
Ing gs, the bilobed arch sh, The primitive shell-sac or enteron or lateral vesicles shell-gland ° of invaginated endoderm, pi, The rectal peduncle or whichwill develop into liver.
During pairing he thrusts the tip of these organs into the seminal vesicles of the female and the eggs are fertilized as they pass out of the oviduct.
The bursting of several of these altered cells is the method by which the skin vesicles are formed in certain conditions.
These vesicles are filled with the colloid material (x 90 diam.) J FIG.
The most remarkable feature of this cystic development is the formation in many genera of several internal buds within a common cyst, each of which forms an independent inverted scolex (Coenurus, Polycercus); or these internal vesicles may bud off a large number of scolices on their external surface (Staphylocystis).
It is probable that these vesicles are not reservoirs, as was at one time thought, but form some special secretion which mixes with that of the testes.
- View of the Base of the Bladder, Prostate, Seminal Vesicles and Vasa Deferentia from behind.
They pass out through short vasa deferentia with internal ciliated funnels, sometimes an enlargement on their course - the seminal vesicles - and a minute external pore situated on the side of the tail.
Which are like those of Chaetopods in (After Goodrich.) structure - viz.vesicles with an intravesicular lens, whereas the eyes of all other Arthropods have essentially another structure, being " cups " of the epidermis, in which a knob-like or rod-like thickening of the cuticle is fitted as refractive medium.