The sexes are distinct (with the exception of a few forms that are hermaphrodite), and the male is always smaller than the female.
The worm inhabits the lung of the frog and toad, and is hermaphrodite (Schneider) or parthenogenetic (Leuckart); the embryos hatched from the eggs find their way through the lungs into the alimentary canal and thence to the exterior; in a few days they develop into a sexual larva, called a Rhabditiform larva, in which the sexes are distinct; the eggs remain within the uterus, and the young when hatched break through its walls and live free in the perivisceral cavity of the mother, devouring the organs of the body until only the outer cuticle is left; this eventually breaks and sets free the young, which are without teeth, and have therefore lost the typical Rhabditis form.
(In Hydra, on the other hand, the individual is usually hermaphrodite.) The medusa always reproduces itself sexually, and in some cases non-sexually also.
The body bears tentacles, but shows no division into hydrorhiza, hydrocaulus or hydranth; it is temporarily fixed and has no perisarc. The polyp is usually hermaphrodite, developing both ovaries and testes in the same individual.
Amphogona, hermaphrodite, with male and female gonads on alternating radial canals.
The fact that all the Euthyneura are hermaphrodite is not a fundamental difference; several Streptoneura are so, likewise Valvata, Oncidiopsis, Marsenina, Odostomia, Bathysciadium, Entoconcha).
Hermaphrodite; head with appendage on right side; radula without central tooth.
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.
Entocolax, mouth at free extremity, animal fixed by aboral orifice of pseudopallium, Pacific. Entoconcha, body elongated and tubular, animal fixed by the oral extremity, protandric hermaphrodite, parasitic in testes of Holothurians causing their abortion.
Enteroxenos, no pseudo pallium and no intestine, hermaphrodite, larvae with operculum.
In the most primitive condition the genital duct is single throughout its length and has a single external aperture; it is therefore said to be monaulic. The hermaphrodite aperture is on the right side near the opening of the pallial cavity, and a ciliated groove conducts the spermatozoa to the penis, which is situated more anteriorly.
A further degree of modification occurs when the male duct takes its origin from the hermaphrodite duct above the external opening, so that there are two distinct apertures, one male and one female, the latter being the original opening.
In front of the osphradium is the single genital pore, the aperture of the common or hermaphrodite duct.
H, Hermaphrodite duct.
K, Opening of the albuphrodite duct, which very soon becomes miniparous gland into P Y the hermaphrodite entwined in the spire of a gland - the duct.
The latter opens e, Hermaphrodite duct into the common duct at the point k, (uterine portion).
Between a fp, fa, k, 1, P, of some days - possibly weeks - the ova of the second Aplysia commence to descend the hermaphrodite duct; they become en FIG.
- Follicles of the hermaphrodite gonads of Euthyneurous Gastropods.
Hermaphrodite genital aperture, connected with the penis by a ciliated groove, except in Actaeon, Lobiger and Cavolinia longirostris, in which the spermiduct is a closed tube.
Genital duct monaulic; hermaphrodite duct connected with penis by a ciliated groove.
U, Hermaphrodite gonad.
The Pulmonata are, like the other Euthyneura, hermaphrodite, with elaborately developed copulatory organs and accessory glands.
From the ovo-testis, which lies near the apex of the visceral coil, a common hermaphrodite duct ve proceeds, which receives the duct of the compact white albuminiparous gland, Ed, and then becomes much enlarged, the additional width being due to the development of glandular folds, which are regarded as forming a uterus u.
Other Pulmonata exhibit variations of secondary importance in the details of this hermaphrodite apparatus.
- Hermaphrodite Reproductive Apparatus of the Garden Snail (Helix horlensis).
In the male of Phyllodromia the rudiment of a vestigial ovary becomes separated from the developing testis, indicating perhaps an originally hermaphrodite condition.
Thus the whole of the Pulmonata (which breathe air, are destitute of gill-plumes and operculum and have a complicated hermaphrodite reproductive system) are either snails or slugs.
The animals being hermaphrodite copulate reciprocally.
Hermaphrodite forms are unknown.
The flowers are hermaphrodite and regular, with the same number and arrangement of parts as in the order Liliaceae, from which they differ in the inconspicuous membranous character of the perianth, the absence of honey or smell, and the brushlike stigmas with long papillae-adaptations to wind-pollination as contrasted with the methods of pollination by insect agency, which characterize the Liliaceae.
The cultivated vine has usually hermaphrodite flowers; but as it occurs in a wild state, or as an escape from cultivation, the flowers manifest a tendency towards unisexuality: that is, one plant bears flowers with stamens only, or only the rudiments of the pistil, while on another plant the flowers are bisexual.
The majority of species are hermaphrodite and many are capable of self-impregnation.
In bisexual or hermaphrodite flowers, that is, those in which both stamens and pistil are present, though self-pollination might seem the obvious course, this is often prevented or hindered by various arrangements which favour cross-pollination.
In some Lamellibranchs - for instance, the European Oyster and the Pisidium pusillum - the sexes are united in the same individual; but here, as in most hermaphrodite animals, the two sexual elements are not ripe in the same individual at the same moment.
These forms are hermaphrodite, with an ovary and testis completely separate from each other on each side of the body, each having its own duct and aperture.
Leptonidae.-Shell thin; no siphons; foot long and byssiferous; marine; hermaphrodite and incubatory.
Cycladidae.-One siphon or two free siphons with simple orifices; pallial line simple; hermaphrodite, embryos incubated in external gill-plate; freshwater, Cyclas; British.
Hermaphrodite, the ovaries and testes distinct, with separate apertures.
The Platyelmia are hermaphrodite and the reproductive organs are complex.
The flowers, which are generally arranged in a cymose inflorescence, are hermaphrodite, hypogynous, and, except in Pelargoniums, regular.
The gonads are paired and hermaphrodite, they form a pair of anterior prolongations of the pericardium, extending nearly to the anterior end of the body.
The flowers are hermaphrodite and regular with parts in fives (pentamerous) throughout, though exceptions from the pentamerous arrangement occur.
18, and Paniceae), and in these the male flower of a spikelet always blooms later than the hermaphrodite, so that its pollen can only effect cross-fertilization upon other spikelets in the same or another plant.
Paniceae (about 25 genera, tropical to subtropical; a few temperate), a second flower, generally male, rarely hermaphrodite, is often present below the fertile flower.