Siphonophore

“ Classification.—The Siphonophora may be divided, following Delage and Hérouard, into four sub-orders:
I. Chondrophorida (Disconectae Haeckel, Tracheophysae Chun) . With an apical chambered pneumatophore, from which tracheal tubes may take origin (fig. 70) ; no nectocalyces or bracts; appendages all on the lower side of the pneumatophore arising from a compact coenosarc, and consisting of a central principal siphon, surrounded by gonosiphons, and these again by tentacles.
Three families: (1) Discalidae, for Discalia and allied genera, deep-sea forms not well known ”

“ This octoradial symmetry, however, is soon lost as the number of folds in the pneumatophore and the number of tentacles increase.
It is probable that in the Siphonophora, as in many other Coelenterata, the production of sexual cells by an individual is no sign that its life-history is completed. There may possibly be two or more phases of life in which sexual maturity is reached. ”

“ Their relations are strikingly illustrated in the instructive group of Siphonophora, as I have briefly shown in my article on "The Cell-soul and Soul-cells" (Deutsche Rundschau, July 1878) . Beyond a doubt the whole stock or polity of Siphonophora has a very definite united will and a united sensibility, and yet each of the individual persons of which this stock (or Cormus) is composed has its own personal will and its own particular sensations. ”

“ The underpart of the foot forms a tube called the funnel (or siphon) . Through the funnel the animal expels water from the mantle cavity, and thus propels itself through the water. When the siphon is in its normal position the animal swims backward; but it can be turned back over the edge of the mantle, giving a forward movement. In cephalopods the sexes are separate, the male being often much smaller than the female. The eggs are usually laid in gelatinous capsules, commonly known in New England as "sea grapes," and the development is direct, that is, without any free-swimming larval stage. ”

“ Gasteropods of the first order have comb-like gills placed in advance of the heart, and are hence termed Prosobranchiata. They are divided into two groups: (a) Siphonostomata (Tube-mouthed) , in which the animal has a long proboscis, and a tube, or siphon, from the breathing-chamber that passes along the anterior canal of the shell, which in this group is well developed. They have a horny operculum, or lid, with which to close the aperture. ”

“ It is often necessary in a laboratory to siphon acids and poisonous liquids. If a pump is used there is always danger of the liquid entering the pump and damaging it, and, besides, a pump is not handy for this purpose. To fill a siphon by suction from the mouth, great care must be taken to keep from drawing the liquid into the mouth. One of the best ways to fill a siphon is to procure a large dropper and having pressed all the air out of the bulb insert the end in the siphon. ”

“ Fischer and Bouvier have made some interesting observations on the breathing of a species of Ampullaria (insularum Orb.) . The species has, in common with all Ampullaria, two siphons, but while the right siphon is but slightly developed, the left is very long, almost twice as long as the shell (see Fig. 65) . The animal, when under the water, lengthens its siphon, brings the orifice to the surface, and by alternately raising and depressing its head produces in the pulmonary sac movements of ex- and inspiration ”

“ A simple experiment with the siphon affords considerable amusement to the little folks, and is well worth trying. Take two tumblers, place them side by side, and fill one with water. Now fill the siphon with water and place the longer end in the empty tumbler, and the shorter one well down in the water of the other. Immediately the laborer will begin to work, pumping water into the empty vessel, and will not stop until he has reduced the water in the full tumbler to a level with the end of the tube. ”

“ A "Columella contiguous to the axis," is when in the centre of the shell and takes the place of the imaginary line which forms its axis.
CONTINUOUS. Carried on without interruption, as the siphon in Spirula, the varices in Ranella, fig. 394, which, occurring in a corresponding part of each whorl, form a continuous ridge.
CONULARIA. Miller. A genus of Orthocerata, described as conical, straight, or nearly so, divided into chambers by imperforate septa; aperture half closed; apex solid, obtuse; external surface finely striated. Resembling Orthoceras, but wanting the siphon. Fig. ”

“ Innumerable forms have been devised adapted for all purposes, and provided with arrangements for filling the tube, or for keeping it full and starting it into action automatically when required. Pipes conveying the water of an aqueduct across a valley and following the contour of the sides are sometimes called siphons, though they do not depend on the principle of the above instrument. In the siphon used as a container for aerated waters a tube passes through the neck of the vessel, one end terminating in a curved spout while the other reaches to the bottom of the interior. ”

“ The siphon is formed by the upper and lower lips, which are produced into a tube with three longitudinal ridges; in the outer grooves are the mandibles, while the inner groove forms the sucking siphon (see transverse section, Fig. 36) . In Ratania, however, there is no siphon. The first antennae possess a great number of joints, and may be geniculated in the male (Cancerilla) . ”

“ Instead of a single relatively large nucleus, each cell is found to contain many small nuclei, and is spoken of as a coenocyte. This character becomes still more pronounced in the large group of the Siphonales. Valoniaceae and Dasycladaceae are partially septate, but elsewhere no cellulose partitions occur, and the thallus is more or less the continuous tube from which the group is named. Yet the siphonaceous algae may assume great variety of form and reach a high degree of differentiation. Protosiphon and Botrydium, on the one hand, are minute vesicles attached to muddy surfaces by rhizoids ”

“ As may be seen, the essential peculiarity of this improvement consists in the very ingenious arrangement that permits of immersing the cocks in the liquid to make them perfectly tight, it being necessary that they should be hermetically closed in order to prevent the entrance of air to the siphon. Everything leads to the belief, then, that if upright siphons have never been able to operate regularly, it has been because no means have been known of expelling the air from the interior without letting air from the exterior enter at the same time. ”

“ The shells of Siphonaria may be known from Limpets by a slight bulging on one side, caused by a radiating groove which interrupts the muscle of attachment. They are marine, and are found on rocks between tide-marks, chiefly in tropical countries.
Cases 99–101. The Limnæidæ are only found in fresh water. Most of them occasionally rise to the surface to breathe, where they glide along foot uppermost, at times suspending themselves by a glutinous thread, after the fashion of a spider. All countries appear to have their peculiar species. ”

“ They show a similar sexual dimorphism to the foregoing family, the adult female being extraordinarily drawn out into finger-like processes (e.g. Philichthys) [54] or else long, slender, and Nematode-like, with much reduced appendages (Lernaeascus) , while the male retains a more normal structure. As in all the foregoing forms there is no siphon.
We now return to two semi-parasitic families, Fam. 8, Nereicolidae, and Fam. 9, Hersiliidae, in which there is certainly no well-developed siphon, but the upper and under lips protrude, forming a hollow between them in which the mouth-parts work. ”

“ The Conchifera are divisible into two sections, Siphonida, from the animals having respiratory siphons, and Asiphonida, destitute of them.
The solen may be taken as a type of the first, and the oyster of the second. The division Siphonida is divided into two sub-sections, those without and those with a pallial line sinuated. The first family of this section is the Pholadidæ, which includes Teredo, Xylophaga, and Pholas, animals which possess extraordinary powers of boring; not merely as the Solens do, through sand, but through the hardest rocks. ”

“ The division of Gasteropodous Molluscs in which the aperture of the shell is not "entire," but possesses a notch or tube for the emission of the respiratory siphon.
SIPHUNCLE (Lat. siphunculus, a little tube) . The tube which connects together the various chambers of the shell of certain Cephalopoda (e.g., the Pearly Nautilus) .
SIRENIA (Gr. seiren. a mermaid) . The order of Mammalia comprising the Dugongs and Manatees.
SIVATHERIUM (Siva, a Hindoo deity; Gr. therion, beast) . An extinct genus of Hoofed Quadrupeds.
SOLIDUNGULA (Lat. solidus, solid; ungula, a hoof) . ”

“ The second section of the Prosobranchiata is termed Siphonostomata, which are characterized by a spiral imperforate shell, the animal of which has sometimes a horny operculum, and is furnished with an elastic trunk, the margin of the mantle acting as a siphon. They are carnivorous. ”

“ The object is to deliver at every upheaval of the handle a certain portion of a fluid disinfectant; formerly it was exclusively Condy's fluid, now it is chloralum. The construction is the essence of simplicity. In a metal, glass, or earthenware vessel, holding a gallon of disinfecting fluid, a metal siphon is fixed, and the bottom is coiled and has a small inlet as shown, by which means the siphon fills itself. When the closet handle is raised, the water rushing down the supply pipe to flush the basin causes a vacuum in the disinfecting siphon, and its contents are blended with the water. ”

“ Genera have been recorded from Silurian and other Palaeozoic horizons, and there is no doubt that the Verticillate Siphoneae of to-day are the remnants of an extremely ancient family, which in former periods was represented by a much more widely distributed and more varied assemblage of species. There is probably no more promising field of work in the domain of fossil algae than the further investigation of the numerous forms included in Munier-Chalmas’ class of Siphoneae 172Verticillatae. ”

“ Now as the leg a is longer than the leg b, the fluid in it weighs more than that in b, and sinking down draws the fluid in b up, and so on till all is drawn from the cask. Syphons are generally made of copper, but gutta-percha would answer exceedingly well. Fig. 2 represents a contrivance for drawing off acids, &c., which would injure the mouth; the ball prevents the acid rising into it, as the mouth is removed directly it begins to fill, which as the instrument is of glass, can easily be seen. ”

“ Finally he took her to where the first siphon was being erected.
“You see,” he explained patiently, “when we come to a valley, or to any depression, we’re compelled to use these immense steel mains. Through them the water is shot down one side and up the other. This one building is ten feet in diameter. In New York, if you remember, there is a siphon bored through solid granite, running beneath the Hudson River, and bringing water from the Catskill Aqueduct. With the exception of a small length of pressure pipe in use at Niagara Falls, our siphons are the largest and longest in the world.” ”

“ The most striking characteristic feature of this division of the Chlorophyceae is the fact that the thallus of a siphoneous alga consists of an unseptate coenocyte; the plant may be extremely small and simple, or it may reach a length of several inches, but in all cases the body does not consist of more than one cell or coenocyte.
From a palaeontological standpoint the Siphoneae are of exceptional interest. It is impossible to do more than refer to a few of the living and fossil genera. ”

“ Entosiphon, visceral mass still coiled; shell much reduced, proboscis very long forming a pseudopallium which covers the whole body and projects beyond in the form of a siphon, foot and nervous system present, eyes, branchia and anus absent, parasite in the Holothurian Deima blakei in the Indian Ocean. ”

“ Tentacles, etc.—The branchial aperture leads through the {45}branchial siphon into the branchial sac. At the base of the siphon, just about the line of junction of the ectoderm of the stomodaeum with the endoderm of the mesenteron, is placed a circle of simple hair-like tentacles (Fig. 18, tn) which stand out at right angles to the wall, and more or less completely meet in the centre to form a delicate, sensory grid or sieve through which all the water entering the body has to pass. ”

“ They always do. Anyway, as I was saying, this creature is much like an ianthina, or snail, of earth. It breathes through a siphon, or tubular proboscis. It uses this siphon to suck in air with which it builds these rafts for itself, to keep its heavy body and shell afloat. It's an adventurer like you, Moljar. ”

“ The nerve cords were dissected out and mounted after staining. Some were imbedded, sectioned and stained. The stain which brought out the cells with greatest clearness was copper haematoxylin.
The general character of the nervous system of sipunculids is well known, and the specimens examined at this time were typical as to the form of the brain and cord. The brain is imbedded in the proboscis just below the tentacles. It has a similar appearance in section to the photographs of Spengel, 1912. The brain is small. Two main branches supply nearby tentacles and muscles. ”