The viscid pulp soon hardens, affording a protection to the seed; in germination the sucker-root penetrates the bark, and a connexion is established with the vascular tissue of the first plant.
Visceral sac and shell small in proportion to the rest of the body, which cannot be withdrawn into the shell; foot elongated, fin-shaped, with sucker, but without operculum.
The body is composed of a small and limited number of segments (not more than fourteen), and there is a sucker at each end of the body.
There is usually fixed above the sucker a short iron valverod, with a device known as a rivet-catcher to prevent damage to the pump by the dropping of rivets from the pump-rods.
A, Fasciola hepatica, from the ventral surface (X 2); the alimentary and nervous systems only shown on the left side of the figure, the excretory only on the right; a, right main branch of the intestine; c, a diverticulum; g, lateral ganglion; n, lateral nerve; o, mouth; p, pharynx; s, ventral sucker; cs, cirrus sac; d, left anterior dorsal excretory vessel; m, main vessel; v, left anterior ventral trunk; x, excretory pore.
The digestive system consists of a simple or bifurcated sac, opening through the mouth by means of a "pharynx bulbosus," adapted to act primarily as a sucker, and secondarily, when drawing blood, as an aspirator.
A, Dorsal view showing the nervous system and digestive system; a, mouth; b, pharynx; c, d, e, gut; E, post-genital union of two limbs of gut; f, excretory pore; g, vaginal pore; h, j, k, brain and nerves; 1, dorsal nerves; m, ventral nerves; n, adoral sucker; o, posterior sucker; p, hooks on posterior sucker; r, vitello-intestinal duct.
In the former case the larva creeps along the tadpole until it reaches the branchial opening into which it darts, fixes its sucker, and then throws off its cilia.
(X7.) D, E, Two views of the chitinous framework of a sucker of Axine belones; highly magnified (after.
If successful, the larva throws off its cilia and develops a dorsal papilla, a median ventral sucker and an additional pair of lateral suckers.
Should it, however, encounter another Diporpa, the mid-ventral sucker of either is applied to the dorsal papilla of the other, and complete fusion takes place across the junction.
"Worms, &c," by perventral sucker which is almost co-extenmission of Macmillan & Co., sive with the lower surface of the body) and is divided into rectangular compartFIG.
(Xioo.) reproductive system; C, Cirrus; H, hooks on the ventral sucker; I, small piece of the intestine to show its connexion with the reproductive organs by the narrow duct that passes from it to the union of the vaginae; M, mouth; 0, ovary; S, oral sucker; SC, sucker; SH, shell-gland; T, Testis; U, uterus; V, vaginal pore; Y, yolkgland.
- Aspido- Aspidocotylean has an oral sucker at the gaster conchicola; anterior extremity and an equally simple ventral aspect; a, post-oral one at the other, thus resembling mouth; b, marginal the members of the next order.
The body grows backwards and the ventral sucker comes to occupy a relatively more anterior position.
The oral sucker may alone be present (Monostomidae), more usually a second is developed on the under surface, but may be mid-ventral (Distomidae) or terminal.
P, Lips of redia; q, collar; r, processes serving as rudimentary feet; s, embryos; 1, trabecula crossing body-cavity of redia; u, glandular cells; v, birth-opening; w, w', morulae; y, oral sucker; y', ventral sucker; z, pharynx.
The principal differences are the complication of the ciliated band, the absence of the excretory organ, the great lateral compression of the body, the possession of a pair of shells protecting the sides, the presence of an organ known as the "pyriform organ," and the occurrence of a sucker in a position corresponding with the depression seen between (m) and (a) in fig.
Fixation takes place by means of this sucker, which is everted for the purpose, part of its epithelium becoming the basal ectoderm of the ancestrula.
The alimentary canal, which may be represented by a vestigial structure, is accordingly not functional, and the larva does not become pelagic. A pyriform organ is present in most Gymnolaemata as well as the sucker by which fixation is effected.
They are called " huitzilin " (spikelet) by the 'Aztecs, and " colibri," " chupaflor " and " chupa-miel " (floweror honey-sucker), and " pajaromosca " (fly-bird) by the Spanish-speaking Mexicans.
In Bdelloidaceae this may alternate with a leech-like gait; the corona being withdrawn, the cupped end of the proboscis serves as a sucker for attachment alternately with the adherent foot, so that the animal loops its way along.
Mimicry is a special form of protective resemblance, differing from ordinary protective resemblance as exemplified by the similarity of the resting goat-sucker to a piece of bark or of leafand stick-insects to the objects after which they are named, in that the imitated object belongs to the animal kingdom and not to the vegetable kingdom or to inorganic nature.
If they spring from a thick root it is not to be wantonly severed, but the soil should be removed and the sucker taken off by cutting away a clean slice of the root, which will then heal and sustain no harm.
In albuminous Monocotyledons the cotyledon itself, probably in consequence of its terminal position, is commonly the agent by which the embryo is thrust out of the seed, and it may function solely as a feeder, its extremity developing as a sucker through which the endosperm is absorbed, or it may become the first green organ, the terminal sucker dropping off with the seed-coat when the endosperm is exhausted.
Wild birds are not very common; among them are the hawk, parrot, owl, woodpecker, kingfisher, green pigeon, African magpie, the honey-sucker and canary.
In the Argasidae the anterior portion of the dorsal surface of the body is extended forwards above the capitulum, so that this structure is concealed from above; the integument is fairly uniformly granular or coriaceous above and below; the palpi are simple and unmodified; there is no sucker beneath the claws in the adult, and there is only a slight structural difference between the sexes.
In the Ixodidae the capitulum is not overlapped by a forward extension of the dorsal area, which is smooth and firmly chitinized either in front or all over; the palpi are usually modified, that is to say, their second and third segments are usually excavated internally to form a sheath for the hypostome; there is a distinct sucker beneath the claws and the difference between the sexes is well marked, the males having the dorsal integument thickly and continuously chitinized, whereas in the females only its anterior portion bears a chitinous plate, the rest of the integument being soft to admit of its distension by the blood which is imbibed in quantity by members of this sex.
14), and the presence of an anterior and posterior sucker, produce a looping mode of progression similar to that of a Geometrid larva.
The sucker-bearing processes of Pneumonoderma are outgrowths of the proboscis.
There seems no doubt that the suctorial mouth-organs of the Diptera have arisen quite independently from those of the Lepidoptera, for in the former order the sucker is formed from the second maxillae, in the latter from the first.
For pumping a well a valved working-barrel with valved sucker is attached to the lower end of the tubing, a perforated " anchor " being placed below.
The sucker carries a series of three or four leather cups, which are pressed against the inner surface of the working barrel by the weight of the column of oil.
The sucker is connected by a string of sucker-rods with the walkingbeam.
Outline of the ventral surface to show the external apertures and nervous system; a, rosette-organ; b, uterine pore; c, terminal sucker; e, vaginal pore; g, male gonopore; n, o, p, nervous system.
- Elongated cylindrical animals either with a single subterminal sucker at the proximal end, or with the corresponding end of the body converted into a mobile undulatory fold.
These complex organs have apparently arisen by the increase in depth and differentiation of an accessory sucker such as is borne on the phyllidia of the former group. Lastly, the scolex of the more familiar Taeniidae (Tetracotylea) carries a rostellum encircled with hooks and four cup-shaped suckers the margins of which do not project beyond the surface of the body.
In Florida, vigorous suckers are sometimes allowed to remain when the plant is cut, and produce a " sucker crop " inferior in character to the first or principal crop, but still serviceable.
The mouth lies usually in the centre of the anterior vzs and sub-terminal sucker or between two adoral suckers, but in Gasterostomum and its allies it is mid-ventral.
In the ectoparasitic Trematodes this post-oral sucker is a complex disk placed near the hinder end and provided With suckerlets, hooks and a musculature arising from a special skeleton.
Thus in the recently discovered arctic genus Prosorhynchus the muscular and glandular extremity is protrusible, but in the allied Gasterostomum this organ is represented by a sucker with fimbriated or tentacular margins.
The chief genital pore is placed anteriorly between the oral sucker and the ventral one, and is posterior only in Holostomidae, Gasterostomidae and a few Distomidae.
C, Epibdella hippoglossi (from Halibut); ms, the two adoral suckers with the mouth (m) between them; ps, ventral sucker; ov, ovary, to testes.
D, Octobothrium merlangi; ms, oral sucker; int.
After a nod of her head, Paulette's hand shot up and the auctioneer all but cheered as he looked about for another sucker, his voice sounding like an old Lucky Strike commercial.