Marsupials may be defined as viviparous (that is non-egglaying) mammals, in which the young are born in an imperfect condition, and almost immediately attached to the teats of the mammary glands; the latter being generally enclosed in a pouch, and the front edge of the pelvis being always furnished with epipubic or "marsupial" bones.
The female is viviparous, and the young, which, unlike the parent, are provided with a long tail, live free in water; it was formerly believed from the frequency with which the legs and feet were attacked by this parasite that the embryo entered the skin directly from the water, but it has been shown by Fedschenko, and confirmed by Manson, Leiper and others, that the larva bores its way into the body of a Cyclops and there undergoes further development.
A, Winged female; B, winged D, viviparous wingless female from in patches from old apple trees, where the insects live in the rough bark and form cankered growths both above and below ground.
Many Gastropoda deposit their eggs, after fertilization, enclosed in capsules; others, as Paludina, are viviparous; others, again, as the Zygobranchia, agree with the Lamellibranch Conchifera (the bivalves) in having simple exits for the ova without glandular walls, and therefore discharge their eggs unenclosed in capsules freely into the sea-water; such unencapsuled eggs are merely enclosed each in its own delicate chorion.
Pedal centres in the form of ganglionated cords; kidney provided with a ureter; viviparous; fluviatile.
Spekia, viviparous, from Lake Tanganyika.
Spire of shell somewhat elongated; mantle-border fringed; viviparous; fluviatile.
No shell; visceral mass not coiled; no sensory organs, nervous system, branchia or anus; body reduced to a more or less tubular sac; hermaphrodite and viviparous; parasitic in Holothurians; larvae are veligers, with shell and operculum.
Prosorhocmus claparedii is a viviparous form.
The female scorpion is viviparous, and the young are produced in a highly developed condition as fully formed scorpions.
Zworo oUvra Ev aurois, viviparous Enaema (= Mammals, including the Whale).
Wotton divides the viviparous quadrupeds into the many-toed, double-hoofed and single-hoofed.
They are unable to move on land, feed on fishes, are viviparous and poisonous.
They are viviparous like the Typhlopidae, upon which they feed besides worms and insects.
These tail-shielded snakes, of which about 40 species are known, are viviparous and burrow in the ground, preferring damp mountainforests.
- The nostrils of these absolutely aquatic, viviparous snakes are valvular and placed on the upper surface of the snout.
These snakes are all very poisonous, mostly viviparous and found in all tropical and subtropical countries, with the exception of Madagascar and New Zealand.
Sea-snakes are viviparous and pass their whole life in the water; they soon die when brought on shore.
The escape of the insect takes place on the spontaneous bursting of the walls of the vesicle, probably when, after viviparous (thelytokous) reproduction for several generations, male winged insects are developed.
Many lizards, however, retain the eggs in the oviducts until the embryo is fully developed; these species then bring forth living young and are called ovo-viviparous by purists.
Naultinus elegans of New Zealand is said to be viviparous; the others lay but one rather large egg at a time.
Some of these comicallooking little creatures are viviparous, others deposit their eggs in the ground.
All the skinks seem to be viviparous, and they prefer dry, sandy ground, in which they burrow and move quickly about in search of their animal food.
That the ichthyosaur was a viviparous animal.
One member of the Cyprinidae is at present known to be viviparous, but no observations have as yet been made on its habits.
One species Callistochiton viviparus is viviparous and its ova develop without a larval stage in the maternal oviduct.
Viviparous plants are an illustration of substitution of vegetative buds for flower.
All the known forms of plant-life are either fungi or allied to them, and many are only microscopic. The most interesting inhabitants of Mammoth Cave are the blind, wingless grasshoppers, with extremely long antennae; blind, colourless crayfish (Cambarus pellucidus, Telk.); and the blind fish, Amblyopsis spelaeus, colourless and viviparous, from 1 in.
Very few Crustacea are viviparous in the sense that the eggs are retained within the body until hatching takes place (some Phyllopoda), but, on the other hand, the great majority carry the eggs in some way or other after their extrusion.
Some species, such as Poa stricta, are known only in this viviparous condition; others, like our British species Festuca ovina, and Poa alpina, become viviparous under the special climatic. conditions.