Quick filters:
Page 1 of 1
Earthworm eggs Stock Photos and Images
RF2NM0383–Oology. Egg clutch of Hooded crow (Corvus cornix) from rural nest. Variegated eggs are represented by the gradient of pattern variability. An earthwor
RF2H4F9FT–Black-headed Gull (Chroicocephalus ridibundus) - Port Althagen Ahrenshoop - Fischland-Darß-Zingst, Baltic Sea, Germany
RM2AJ093P–Outlines of zoology . ormfrom its hole. As each of the four longitudinal rows is double, thereare obviously eight bristles to each ring. On the skin of the ventral EARTHWORM. 213 surface there are not a few special apertures, which.should be looked for on a full-grown worm ; but careful examination of several specimens is usually necessary. Almost always plain on the 15th ring are the two swollen lips of the male ducts, less dibtinct on the 14th are the apertures of the oviducts through which the eggs pass, while on each side, between segments 9 and 10, 10 and II, are the openings of two recep
RF2KX7HNT–Oology. Egg clutch of Hooded crow (Corvus cornix) from rural nest. Variegated eggs are represented by the gradient of pattern variability. An earthwor
RF2H4F9EH–Black-headed Gull (Chroicocephalus ridibundus) - Port Althagen Ahrenshoop - Fischland-Darß-Zingst, Baltic Sea, Germany
RM2AJFNRJ–The cell in development and inheritance . eggs of Cyma-togaster (Hubbard, 94) Syngnathns (Henneguy, 96), the earthworm(Calkins, 95, Foot, 96), Polyzoiiiiini and other myriapods (Nemec,97, Van Bambeke, 98), LinndiLS (Munson, 98), Cypris (Woltereck,98), and Molgida (Crampton, 99). In nearly all of these forms theyolk-nucleus first appears in the form of a cap closely applied to oneside of the nucleus (Figs. 80, 81), sometimes so closely united to thelatter that it is difficult to trace a boundary between them. At alater period the yolk-nucleus moves away from the nucleus and in GROWTH AND DIFFER
RF2P8R23K–Oology. Egg clutch of Hooded crow (Corvus cornix) from rural nest. Variegated eggs are represented by the gradient of pattern variability. An earthwor
RF2H4F9HG–Black-headed Gull (Chroicocephalus ridibundus) - Port Althagen Ahrenshoop - Fischland-Darß-Zingst, Baltic Sea, Germany
RM2CEG0G3–. Towards racial health : a handbook on the training of boys and girls, parents, teachers & social workers. ther earth-worm to join with its eggs. But here is a great differ-ence. The tulip grew fixed in the ground, so had toget the insects to help it, and to bring the sperms fromone tulip to another. • The earthworm can crawl; itis not fixed in the ground, and so it does not need to bedependent upon anything else to help it; it can do thisgreat work for itself ; so one earthworm crawls to anotherearthworm and gives it the sperms that it needs to 112 NATURE STUDY join with its eggs. Then the l
RF2H4F9CT–Black-headed Gull (Chroicocephalus ridibundus) - Port Althagen Ahrenshoop - Fischland-Darß-Zingst, Baltic Sea, Germany
RM2CE5TNC–. Home geography for primary grades . A .MOTH. THE STORY OF THE SILKWORM. A silkworm is not a real worm, but an insect.True worms remain worms during the whole of theirlife history. The common earthworm which you seeupon the ground after a rain is a real worm. The life history of an insect is not at all likethat of a worm. Each of the eggs of an insecthatches into a little worm-like animal, or caterpillar.After living a number of days the caterpillar changesinto a pupa or chrysalis. In this condition it has ahard case and is helpless. Now it undergoes a slow 221. 222 HOME GEOGRAPHY. change and
RM2CEG0CH–. Towards racial health : a handbook on the training of boys and girls, parents, teachers & social workers. The eggs laid in anoval mass, on water-weed, stones, etc. examining an earthworm, the enlarged creamy-colouredracial organs shining through the skin a short distancebehind the head end and in front of the thickened partof the earthworm, known as the * saddle. Water-snails reproduce in a manner similar to theearthworm, being hermaphrodite and cross-fertilised.One can often see, during the spring and summer, thisprocess of giving taking place if one keeps water-snails in a simple aquarium
RMRJD41X–. The cell in development and inheritance. Cells. GROWTH AND DIFFERENriAriON OF THE GERM-CELLS II5 cells of the Qg^ which have sacrificed their own development for the sake of their companions, or whether they have had a distinct origin from a very early period. That the former alternative is possible is shown bv the fact that such a sacrifice occurs in some animals after the eggs have been laid. Thus in the earthworm, Liiuibricus tcrrcs- ti'is, several eggs are laid, but only one develops into an embryo, and the latter devours the undeveloped eggs. A similar process occurs in the marine gaste
RMRDGHAT–. An introduction to zoology, with directions for practical work (invertebrates). Vll ANNELIDA 91 Beproduction.. jaws, with which the creature, having fixed itself by its mouth-sucker to an animal, makes a small wound; through this it can suck the blood of its victim, which may be almost any creature to which it can attach itself. Leeches lay eggs which are surrounded by little transparent capsules, and are deposited on submerged water-weeds, or on the damp ground close to the water. The cocoon is formed in the same way as that of the earthworm, the two ends closing when the leech has slipped
RMRJD418–. The cell in development and inheritance. Cells; Cells. • GROWTH AND DIFFERENTIATION OF THE GERM-CELLS II5 cells of the Q.g^ which have sacrificed their own development for the sake of their companions, or whether they have had a distinct origin from a very early period. That the former alternative is possible is shown by the fact that such a sacrifice occurs in some animals after the eggs have been laid. Thus in the earthworm, LiinibriciLS terres- tris, several eggs are laid, but only one develops into an embryo, and the latter devours the undeveloped eggs. A similar process occurs in the ma
![. A first book of zoology [microform]. Zoology; Zoologie. H ZOOLOGY tilizing substance and egga, but just as in plants the ova are generally fertilized by means of the pollen from another plant, so also in the worm cross-fertilization occurs. When the eggs are about to be laid, the skin in the clitellum region actively secretes or produces a fluid which exposure to the air converts into an elastic substance. Thus the clitellum region appears to be surrounded by a broad elastic ring or cocoon. The earthworm next begins to wriggle backwards out of the cocoon, and so the latter is pushed nearer a Stock Photo](https://c8.alamy.com/comp/REPBDC/a-first-book-of-zoology-microform-zoology-zoologie-h-zoology-tilizing-substance-and-egga-but-just-as-in-plants-the-ova-are-generally-fertilized-by-means-of-the-pollen-from-another-plant-so-also-in-the-worm-cross-fertilization-occurs-when-the-eggs-are-about-to-be-laid-the-skin-in-the-clitellum-region-actively-secretes-or-produces-a-fluid-which-exposure-to-the-air-converts-into-an-elastic-substance-thus-the-clitellum-region-appears-to-be-surrounded-by-a-broad-elastic-ring-or-cocoon-the-earthworm-next-begins-to-wriggle-backwards-out-of-the-cocoon-and-so-the-latter-is-pushed-nearer-a-REPBDC.jpg ". A first book of zoology [microform]. Zoology; Zoologie. H ZOOLOGY tilizing substance and egga, but just as in plants the ova are generally fertilized by means of the pollen from another plant, so also in the worm cross-fertilization occurs. When the eggs are about to be laid, the skin in the clitellum region actively secretes or produces a fluid which exposure to the air converts into an elastic substance. Thus the clitellum region appears to be surrounded by a broad elastic ring or cocoon. The earthworm next begins to wriggle backwards out of the cocoon, and so the latter is pushed nearer a Stock Photo")
RMREPBDC–. A first book of zoology [microform]. Zoology; Zoologie. H ZOOLOGY tilizing substance and egga, but just as in plants the ova are generally fertilized by means of the pollen from another plant, so also in the worm cross-fertilization occurs. When the eggs are about to be laid, the skin in the clitellum region actively secretes or produces a fluid which exposure to the air converts into an elastic substance. Thus the clitellum region appears to be surrounded by a broad elastic ring or cocoon. The earthworm next begins to wriggle backwards out of the cocoon, and so the latter is pushed nearer a
![. Outlines of zoology. Zoology. MALE CELL OR SPERMATOZOON. 57 earthworm, in which several eggs are wrapped up to- gether. Male cell or spermatozoon.—This is a much smaller and usually a much more active cell than the ovum. In its minute size, locomotor energy, and persistent vitality, it resembles a flagellate monad, while the ovum is comparable to an Amoeba or to one of the more encysted Protozoa. A spermatozoon has usually three distinct parts: the essential "head," consisting mainly of nucleus, and the mobile "tail," which is often fibrillated, and a small middle portion Stock Photo](https://c8.alamy.com/comp/RDP0EB/outlines-of-zoology-zoology-male-cell-or-spermatozoon-57-earthworm-in-which-several-eggs-are-wrapped-up-to-gether-male-cell-or-spermatozoonthis-is-a-much-smaller-and-usually-a-much-more-active-cell-than-the-ovum-in-its-minute-size-locomotor-energy-and-persistent-vitality-it-resembles-a-flagellate-monad-while-the-ovum-is-comparable-to-an-amoeba-or-to-one-of-the-more-encysted-protozoa-a-spermatozoon-has-usually-three-distinct-parts-the-essential-quotheadquot-consisting-mainly-of-nucleus-and-the-mobile-quottailquot-which-is-often-fibrillated-and-a-small-middle-portion-RDP0EB.jpg ". Outlines of zoology. Zoology. MALE CELL OR SPERMATOZOON. 57 earthworm, in which several eggs are wrapped up to- gether. Male cell or spermatozoon.—This is a much smaller and usually a much more active cell than the ovum. In its minute size, locomotor energy, and persistent vitality, it resembles a flagellate monad, while the ovum is comparable to an Amoeba or to one of the more encysted Protozoa. A spermatozoon has usually three distinct parts: the essential "head," consisting mainly of nucleus, and the mobile "tail," which is often fibrillated, and a small middle portion Stock Photo")
RMRDP0EB–. Outlines of zoology. Zoology. MALE CELL OR SPERMATOZOON. 57 earthworm, in which several eggs are wrapped up to- gether. Male cell or spermatozoon.—This is a much smaller and usually a much more active cell than the ovum. In its minute size, locomotor energy, and persistent vitality, it resembles a flagellate monad, while the ovum is comparable to an Amoeba or to one of the more encysted Protozoa. A spermatozoon has usually three distinct parts: the essential "head," consisting mainly of nucleus, and the mobile "tail," which is often fibrillated, and a small middle portion
RMRDHCYN–. A manual of elementary zoology . Zoology. ANNELIDA : THE EARTHWORM, NEREIS 229 worm, along a groove, into the spermathecse of the other, after which the worms separate. The eggs are laid in a cocoon, which is secreted by the clitellum as a broad band round the body and passed forwards over the head. The cocoon contains a nutrient fluid, and into it sperm which has been received from another worm is transferred in a little packet or spefmatophore. In passing over the head -p.v.s.. Fig. 146.—A dissection of the reproductive organs of an earth- worm. The dissection is made from above, and the m
![. The cell in development and inheritance. Cells. Fig. 61. — Young ovarian eggs of the earthworm (Lumbricus), showing yolk-nucleus. [Calkins.] A. Very early stage ; the irregular yolk-nucleus (>'.«.) closely applied to the germinal vesicle and staining like chromatin. B. Later stage; the yolk-nucleus separating from the germinal vesicle and changing its staining-power. C. Still later stage; the yolk-nucleus broken up into rounded bodies staining like the cytoplasm. here first appears as an irregular granular body lying directly on the nuclear wall, which in some cases appears to be interrup Stock Photo](https://c8.alamy.com/comp/RJD3RJ/the-cell-in-development-and-inheritance-cells-fig-61-young-ovarian-eggs-of-the-earthworm-lumbricus-showing-yolk-nucleus-calkins-a-very-early-stage-the-irregular-yolk-nucleus-gt-closely-applied-to-the-germinal-vesicle-and-staining-like-chromatin-b-later-stage-the-yolk-nucleus-separating-from-the-germinal-vesicle-and-changing-its-staining-power-c-still-later-stage-the-yolk-nucleus-broken-up-into-rounded-bodies-staining-like-the-cytoplasm-here-first-appears-as-an-irregular-granular-body-lying-directly-on-the-nuclear-wall-which-in-some-cases-appears-to-be-interrup-RJD3RJ.jpg ". The cell in development and inheritance. Cells. Fig. 61. — Young ovarian eggs of the earthworm (Lumbricus), showing yolk-nucleus. [Calkins.] A. Very early stage ; the irregular yolk-nucleus (>'.«.) closely applied to the germinal vesicle and staining like chromatin. B. Later stage; the yolk-nucleus separating from the germinal vesicle and changing its staining-power. C. Still later stage; the yolk-nucleus broken up into rounded bodies staining like the cytoplasm. here first appears as an irregular granular body lying directly on the nuclear wall, which in some cases appears to be interrup Stock Photo")
RMRJD3RJ–. The cell in development and inheritance. Cells. Fig. 61. — Young ovarian eggs of the earthworm (Lumbricus), showing yolk-nucleus. [Calkins.] A. Very early stage ; the irregular yolk-nucleus (>'.«.) closely applied to the germinal vesicle and staining like chromatin. B. Later stage; the yolk-nucleus separating from the germinal vesicle and changing its staining-power. C. Still later stage; the yolk-nucleus broken up into rounded bodies staining like the cytoplasm. here first appears as an irregular granular body lying directly on the nuclear wall, which in some cases appears to be interrup
RMRHK9JA–. Biology. Biology. EMBRYOLOGY OF THE EARTHWORM 159 layered gastrula. Up to this stage, development closely follows the type described on page 79, but from here on, it becomes complicated by the formation of a third germ layer, called the mesoderm. This arises from two pole cells, coming from the vegetative pole and taking an initial position in the segmenta- tion cavity (Fig. 66). They then divide, forming a sheath of cells on each side of the median line and filling the segmentation. FIG. 65.—A, Egg capsule, enlarged five diameters (a few eggs, ov., are shown near by on the right enlarged to
RMRHJX1N–. Biology; the story of living things. sperm. ...mesooCarm. mesoderm onus V. segments 9 and 10, it receives sperm cells from the other worm that have been stored there. The girdle is passed down over the anterior end of the worm, slipped off, forming a closed case which contains the eggs, sperms, and a nutritive fluid. These capsules may be found in late spring under stones, boards, logs, or in manure heaps. After fertilization, the egg of the earthworm divides first into two, then four, then eight cells, and so on, continuing until a hollow ball of cells, called a hlastula, is formed. These c
RMRHJX19–. Biology; the story of living things. ...mesooCarm. mesoderm onus V. segments 9 and 10, it receives sperm cells from the other worm that have been stored there. The girdle is passed down over the anterior end of the worm, slipped off, forming a closed case which contains the eggs, sperms, and a nutritive fluid. These capsules may be found in late spring under stones, boards, logs, or in manure heaps. After fertilization, the egg of the earthworm divides first into two, then four, then eight cells, and so on, continuing until a hollow ball of cells, called a hlastula, is formed. These cells ar
![. The cell in development and inheritance. Cells; Cells. I20 THE GERM-CELLS uncertain whether the bodies thus arising have the same physiologi- cal significance as the "yolk-nuclei" of cytoplasmic origin. Calkins ('95J i)' working in my laboratory, has brought forward strong evi- dence that the "yolk-nucleus" of Litnibriciis is derived from a sub- stance nearly related with chromatin (Fig. 61). The yolk-nucleus. Fig. 61. — Young ovarian eggs of thie earthworm {Lumbricus), showing yolk-nucleus. {Calkins.] A. Very early stage; the irregular yolk-nucleus {y.n.) closely applied Stock Photo](https://c8.alamy.com/comp/RJD3TH/the-cell-in-development-and-inheritance-cells-cells-i20-the-germ-cells-uncertain-whether-the-bodies-thus-arising-have-the-same-physiologi-cal-significance-as-the-quotyolk-nucleiquot-of-cytoplasmic-origin-calkins-95j-i-working-in-my-laboratory-has-brought-forward-strong-evi-dence-that-the-quotyolk-nucleusquot-of-litnibriciis-is-derived-from-a-sub-stance-nearly-related-with-chromatin-fig-61-the-yolk-nucleus-fig-61-young-ovarian-eggs-of-thie-earthworm-lumbricus-showing-yolk-nucleus-calkins-a-very-early-stage-the-irregular-yolk-nucleus-yn-closely-applied-RJD3TH.jpg ". The cell in development and inheritance. Cells; Cells. I20 THE GERM-CELLS uncertain whether the bodies thus arising have the same physiologi- cal significance as the "yolk-nuclei" of cytoplasmic origin. Calkins ('95J i)' working in my laboratory, has brought forward strong evi- dence that the "yolk-nucleus" of Litnibriciis is derived from a sub- stance nearly related with chromatin (Fig. 61). The yolk-nucleus. Fig. 61. — Young ovarian eggs of thie earthworm {Lumbricus), showing yolk-nucleus. {Calkins.] A. Very early stage; the irregular yolk-nucleus {y.n.) closely applied Stock Photo")
RMRJD3TH–. The cell in development and inheritance. Cells; Cells. I20 THE GERM-CELLS uncertain whether the bodies thus arising have the same physiologi- cal significance as the "yolk-nuclei" of cytoplasmic origin. Calkins ('95J i)' working in my laboratory, has brought forward strong evi- dence that the "yolk-nucleus" of Litnibriciis is derived from a sub- stance nearly related with chromatin (Fig. 61). The yolk-nucleus. Fig. 61. — Young ovarian eggs of thie earthworm {Lumbricus), showing yolk-nucleus. {Calkins.] A. Very early stage; the irregular yolk-nucleus {y.n.) closely applied
RMRE0C5A–. The germ-cell cycle in animals . Cells. 190 GERM-CELL CYCLE IN ANIMALS All the species of Metazoa may be separated into two groups. The individuals in one group of species. Fig. 56. — Diagram of the reproductive organs of the earthworm, dorsal view. A, B, C, seminal vesicles; N, nerve-cord; O, ovary; OD, ovi- duct ; R, egg sac; <S, spermatheca; SF, seminal funnel; T, testes; VD, vas deferens. (From Marshall and Hurst.) possess only one sort of reproductive organs (male or female) and produce only one sort of germ cells (eggs or spermatozoa); these species are said to be dice-. Please note
Search Results for Earthworm eggs Stock Photos and Images (42)
Page 1 of 1