It is presumable that here, as in the Algæ, the spermatozoids introduce themselves into the cavity of the oogonium, and unite with the gonospheres.
These rod-like corpuscles, which resemble the spermatozoids in Vaucheria, have their movements assisted by a long cilium.
They resemble in their organization and agility the spermatozoids of Achlya dioica.
Similar spermatozoids were observed in some species of Zamia by H.
Pg) hangs down into the pollen-chamber; two large spirally ciliated spermatozoids are produced, their manner of development agreeing very closely with that of the corresponding cells in Cycas and Zamia.
Proximal end of Pollen-tube, a, a, Spermatozoids from G of fig.
The spermatozoids constitute the most striking link with both cycads and ferns.
The outermost cell, by the division of the remaining nucleus, produces two large spermatozoids (fig.
Defn: One of the motionless spermatozoids in the conceptacles of certain fungi.
It is a white or whitish viscid fluid secreted by the testes, characterized by the presence of spermatozoids to which it owes its generative power.
Some time ago it was shown that the spermatozoids steered a decided course towards the archegonia, but the reason for this has only been comparatively recently explained.
Should there be sufficient moisture about, the spermatozoidswhich are produced by the antheridium swim towards the archegonia in any female prothallus which may be near.
The prothallus and the male organ (antheridium) are comparable to the special cell-group in the pollen-grain, whilst the spermatozoids approximate to the generative cells.
However that may be, as soon as the underside of the prothallus has become thoroughly wetted the antheridia open, and certain little bodies called spermatozoids are allowed to escape.
The spermatozoids unite with the various egg cells, and in this way an embryo is formed which finally develops into the mature plant.
As in the case of the other Vascular Cryptogams which have been considered, spermatozoidsare produced in the antheridia.
Although the nature of the substance is not exactly known, it is suggested that this may be malic acid, seeing that experiments have shown that the spermatozoids are attracted to this product when it is artificially introduced.
Although there is quite a competition amongst the spermatozoids as to which shall enter the archegonium, it is likely that only one actually succeeds in entering the egg cell.
The spermatozoids of a peat moss are shown in Figure 60, D.
After a few minutes this membrane is dissolved, and the spermatozoids are set free.
If a ripe antheridium is crushed in a drop of water, after lying a few minutes the spermatozoids will escape through small openings in the side of the cells.
K, mass ofspermatozoids surrounded by the inner membrane of the antheridium.
Owing to their small size the spermatozoids are difficult to see satisfactorily and other mosses (e.
Occasionally one of these spermatozoids may be found attached to the trichogyne, and in this way fertilization is effected.
No spermatozoids are produced, the seed plants differing in this respect from all pteridophytes.
They separate at the time of fertilization to allow the spermatozoids to enter the oögonium.
After lying a few moments in the water, the wall of each sperm cell becomes completely dissolved, and the spermatozoids are released, and swim rapidly away with a twisting movement.
The spermatozoids are excessively small, and resemble those of the bryophytes.
To see the cilia it is necessary to kill the spermatozoids with iodine or some other reagent.
In G, one of the antheridia has discharged the mass of spermatozoids (an.
One of the motionless spermatozoids in the conceptacles of certain fungi.
If, from pathological causes the entry of several spermatozoids takes place, there results, according to Fol, a double or triple monster.
On some occasions a squad of spermatozoids advances to meet the descending egg, and numerous spermatozoids are often found in the tubes, even as far as the abdominal cavity.
Naegeli at once recognised their essential agreement with the antheridia already known in the Bryophytes and compared the spermatozoids with the corresponding structures in animals.
Seeing that the female organs (spores) arise on the frond at a much later stage of development, and long after the pro-embryo has died away, the function of the spermatozoids is far from evident.
It is now generally admitted that, in the Vascular Cryptogams, as also in Mosses and Liverworts, the bodies of the spermatozoids are formed by the nuclei of the cells from which they arise.
Furthermore, the spermatozoids in the mosses and vascular cryptogams throw off a small vesicle before performing their functions[153].
The eggs and the spermatozoids proceeding from these two forms differ sensibly from one another, and the difference of form corresponds with that of origin.
We see thus among some of them different males; among others different females: then eggs and spermatozoids equally different in one and the same animal species.
Ginkgo and cycas spermatozoids were provided, yeast of the native wine, fossil slides under the microscope--all in working order.
Each protuberance bursts, and some of the spermatozoids come in contact with and are absorbed by the oosphere, which then secretes a cell-wall, and after a time germinates.
The protoplasm of the other protuberance divides into many small masses, furnished with cilia, the spermatozoids or male cells.
Reproduction by division, or by single cells being converted into new families; and by resting spores formed from some of the cells after impregnation by spermatozoids formed from the contents of other cells of the same family.
Fructification: zoospores produced from the cell contents of the filaments; resting spores formed from the contents of particular cells after impregnation by ciliated spermatozoids produced in distinct antheridial cells.
Reproduction by zoospores formed of the whole contents of a cell, with a crown of numerous cilia; resting spores formed in sporangial cells after fecundation by ciliated spermatozoids formed in antheridial cells.
Atrophy and diminished weight of the testicles and rarity or absence of the spermatozoids are indications of senility; although spermatozoids have been observed at ninety-four years.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "spermatozoids" in a variety of sentences. We hope that you will now be able to make sentences using this word.
