After fertilization the ovule is greatly changed, in connexion with the formation of the embryo.
As the endosperm increases in size along with the embryo-sac and the embryo, the substance of the original nucellus of the ovule is gradually absorbed.
The seed is formed from theovule as the result of fertilization.
In other species the infection occurs through the style of the flower, but the fungus after reaching the ovule develops no further during that year but remains dormant in the embryo of the seed.
The radicular extremity points towards the micropyle, while the cotyledonary extremity is pointed towards the base of the ovule or the chalaza.
This is seen in the passion-flower, where the covering arises from the placenta or extremity of the funicle at the base of the ovule and passes upwards towards the apex, leaving the micropyle uncovered.
Pollen of one variety may not combine with the ovule of another variety or species but may stimulate the ovule to go on and develop all alone, without taking to itself the added pollen.
Before a child is possible, however, theovule must meet the egg from the male.
After menstruation is over, the womb begins again to prepare itself for the coming of the next ovule or egg, and as this occurs every twenty-eight days, menstruation is commonly termed the "monthly periods.
The ovule we may regard as the human female egg, and one ripens and falls out every twenty-eight days.
We have seen that the ovule from the ovary is the female egg, or principle.
The ovule or egg is now in the cavity of the womb where we will leave it for the present.
This lining becomes congested with blood, and is so intensely swollen at the time when the ovule or egg reaches the womb, that it is ready to rupture and bleed all over its surface.
Emphasize to your daughter that the female ovule or egg, and the male egg, or spermatozoa, are minute objects, so microscopically small that a hundred million of them could comfortably lie upon a ten-cent piece.
At the same time an extra amount of blood is sent to the womb to provide nourishing material for the ovule to use in its growth.
In the other, we have the ovule developed into the fœtus within the body of the parent, and the young animal is then brought forth in a more or less complete state of development, to be nourished by the parental secretion called milk.
On the one hand, we have a system of reproduction by which the ovule is brought forth from the body of the parent in an inclosed vessel, and thereafter derives nothing from the parental body.
And when a pollen grain lands on a pistil and joins with the ovule prepared in the ovary, the two components are united again.
The spermatozoon penetrates into the ovule and becomes fused with it.
The ovule is a minute cell with a transparent membrane, within which is the yolk containing the germinal vesicle.
Carpels formed of 5 ovaries, free, unilocular, containing one ovule each.
An analogous mass of protoplasm in the ovule of a flowering plant; an embryonic vesicle.
The condition of an ovule having but a single embryo.
Having the axis of an ovule or seed straight from the hilum and chalaza to the orifice or the micropyle; atropous.
Capable of being impregnated, as the egg of an animal, or the ovule of a plant.
Inclined or hanging downwards, as a flower on a recurved stalk, or an ovulewhich hangs from the upper part of the ovary.
The continuation of the seed stalk along the side of an anatropous ovule or seed, forming a ridge or seam.
Having the embryo or ovule oblique or transverse to the funiculus; amphitropous.
The series of cells formed in the ovule of a flowering plant after fertilization, but before the formation of the embryo.
A cellular layer derived from the nucleus of an ovule and surrounding the embryo sac.
A fertilized o\'94sphere in the ovule of a flowering plant.
When this has happened, the ovule begins to grow and to develop into a seed.
The pollen grain is like the ovule in structure, only much smaller.
The ovule is a part of every ovary just as the pollen is a part of every anther.
Each ovule is attached to the pod by a little stem which can also be seen with the light shining through the pod.
Every ovule has a tiny opening, or micropyle as it is called, and it is now easy to guess what that is for.
The older child can add to his stock of facts, and one of the things he will be likely to want to know is how the little pollen grain up on the stigma can influence the ovuledown in the ovary.
That the seed inherits equally from the ovule and the pollen grain is a truth that should be impressed in many ways.
As the bird approaches maturity, one ovary and its oviduct enlarge, and the ova, which develop from the inside of the ovary just as the ovule develops inside the flower ovary, also become large.
No ovule can possibly grow into a grain without this tiny bit of pollen.
It not only assists the ovule to develop, but it impresses upon it its own characteristics.
When the ovule has developed in this way we call it a seed.
Ovary 10-celled, with a single ovule in each cell.
Flowers dioecious, axillary and solitary, the fertile consisting of a naked erect ovule which becomes a bony-coated seed more or less surrounded or enclosed by the enlarged fleshy disk (or scale).
Ovary 2--4-celled, with an erect anatropous ovule in each cell.
Flowers with a manifest calyx, or calyx and corolla, and a singleovule suspended from the summit of each cell.
Of his many important statements I will here give only a single one as an example, namely, that "every ovule in a pod of Crinum capense fertilised by C.
The ovule is curved upon itself, so that the micropyle is near the funicle.
When theovule is so developed that the chalaza is at the hilum (next the placenta), and the micropyle is at the opposite extremity, there being a short funicle, the ovule is orthotropous.
The position of the ovule relative to the ovary varies.
The anatropous ovule arises from the placenta as a straight or only slightly curved cellular process, and as it grows, gradually becomes inverted, curving from the point of origin of the integuments (cf.
The ovule is attached to the placenta either directly, when it is sessile, or by means of a prolongation funicle (fig.
In Cycas the altered leaf, upon the margin of which the ovule is produced, and the peltate scales, from which they are pendulous in Zamia, are regarded by all botanists as carpellary leaves.
In such an ovule a straight line drawn from the hilum to the micropyle passes along the axis of the ovule.
As the seed develops from the ovulewhich has been fertilized by the pollen, the essential structures for seed-production are two, viz.
St. Hilaire of an erect and suspended ovule in the same ovarium, but perhaps this hardly bears on the point.
The result of fertilization is the development of the ovule into the seed.
Dorsiventrality is also clearly derived from radial construction, and anatropy of the ovule has followed atropy.
We thus learn that an ovule is not indispensable for the reception of the influence of the male element.
The fruit-character indicates an affinity with Boraginaceae from which, however, they differ in habit and by characters of ovule and embryo.
Lastly, when the pollen crept in at the tiny opening we learnt that the ovule had now all it wanted to grow into a perfect seed.
The various terms which define the position or direction of the ovule (erect, ascending, etc.
Campylotropous ovule of a Chickweed: c, hilum and chalaza; f, orifice.
Like the ovule from which it originates, a seed consists of coats and kernel.
Anatropous ovule of a Violet, the parts lettered as in the last.
The annexed two figures are sections of such an ovule at maturity; and Fig.
It will serve all purposes to call them simply outer and inner ovule coats.
In structure an ovuleis a pulpy mass of tissue, usually with one or two coats or coverings.
It is also evident that should the pollen continue to fertilize the ovule in the same flower, the plants in successive generations might become weakened and finally die out and the species be lost.
The parts of a flower that are necessary to produce seeds are the pistil, with its stigma at the top and ovule at the base, and the stamens with their pollen-laden anthers.
G, f), the body of the ovule being bent up so as to lie against the stalk.
Owing to the large size and consequent opacity of the ovules, as well as to the difficulty of getting the early stages, the development and finer structure of the ovule will not be discussed here.
One side of the ovule grows much faster than the other, so that it is completely bent upon itself, and the opening between the integuments is brought close to the base of the ovule (Fig.
The embryo is elongated with a circle of small leaves at the end away from the opening of the ovule toward which is directed the root of the embryo.
We find now that the ovule is attached to a stalk (funiculus) (Fig.
A careful longitudinal section of the scale through the ovule will show the general structure.
By carefully opening the ovary and slightly crushing it in a drop of water, the pollen tube may sometimes be seen growing along the stalk of the ovule until it reaches and enters the micropyle.
G, longitudinal section through a full-grown ovule of the Scotch pine.
Turn back to the figure (page 54) showing the ovule in the ovary.
When it reaches the ovary, the sperm cell penetrates an ovule by making its way through a little hole called the micropyle.
From that time on there is a growth of the fertilized egg within the ovule which makes a baby plant called the embryo.
One way of solving the problem was for pollination to take place while the megaspore was still on the parent plant, and this is just what the formation of an ovule or seed was likely to secure.
On the full development of the diploid embryo of the next generation, the diploid ovule of the preceding diploid generation is separated from the latter as a ripe seed.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "ovule" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: albumen; caviar; egg; eggshell; ellipse; oval; ovoid; ovule; seed; spawn; white; yellow
