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"Sense-epithelium cell of Aurelia." — Encyclopedia Britannica, 1893

Epithelium

"Sense-epithelium cell of Aurelia." — Encyclopedia Britannica, 1893

"Eudorina. A colony of 16 flagellate cells imbedded in a gelatinous matrix." — Galloway

Eudorina

"Eudorina. A colony of 16 flagellate cells imbedded in a gelatinous matrix." — Galloway

"Young resin gland of fir: <em>a</em>, duct, an intercellular space formed by the separation of the four nucleate cells." &mdash; Coulter, 1910

Resin gland of a fir

"Young resin gland of fir: a, duct, an intercellular space formed by the separation of the…

"The telephone standard and compound forms of Fuller cell... The Fuller cell is of the double fluid cariety and has the advantage over the Grenet type, in that the zinc is always kept well amalgamated and does not require removal from the solution." -Hawkins, 1917

Fuller Cell

"The telephone standard and compound forms of Fuller cell... The Fuller cell is of the double fluid…

"The convoluted gland is seen surrounded by fat cells and may be traced through the true skin to its outlet in the horny layers of the outer skin." &mdash; Blaisedell, 1904

Sweat gland

"The convoluted gland is seen surrounded by fat cells and may be traced through the true skin to its…

"The electric resistance of the porous cup employed in the Daniel cell, and the local action produced by the material of which is it composed, led to the invention of similar cells in which it is dispensed with, the gravity cell." --Atkinson 1903

Gravity Cell

"The electric resistance of the porous cup employed in the Daniel cell, and the local action produced…

"The elements are zinc and carbon. In the Greet cell, a zinc plate is suspended b a rod between two carbon plates, so that it does not touch them, and when the cell is not in use the zinc is withdrawn from the solution..." -Hawkins, 1917

Grenet Cell

"The elements are zinc and carbon. In the Greet cell, a zinc plate is suspended b a rod between two…

"...and is constructed with a zinc plate suspended between two carbon plates, so as to have two carbon surfaces exposed to the direct action of two zinc surfaces, and as close to them as praticable without contact, to reduce teh electric resistance through the fluid to the lowest degree." -Atkinson 1903

Grenet Cell

"...and is constructed with a zinc plate suspended between two carbon plates, so as to have two carbon…

"...and is constructed with a zinc plate suspended between two carbon plates, so as to have two carbon surfaces exposed to the direct action of two zinc surfaces, and as close to them as praticable without contact, to reduce teh electric resistance through the fluid to the lowest degree." -Atkinson 1903

Grenet Cell

"...and is constructed with a zinc plate suspended between two carbon plates, so as to have two carbon…

"Cross-section of One Half of a Human Hair. A hair is made up of horny cells of the outer layer of the skin altered in shape and structure." &mdash; Blaisedell, 1904

Cross-section of a human hair

"Cross-section of One Half of a Human Hair. A hair is made up of horny cells of the outer layer of the…

"Nettling cells of Hydra. A, unexploded; B, exploded; b, barbs; c, the nettling cell in which the nettling organ is developed; cn., the cnidocil or "trigger"; cp., the capsule or nettling organ; f, the nettling filament or lasso; n, neck of the capsule; nu., nucleus of the cell." &mdash; Galloway

Hydra

"Nettling cells of Hydra. A, unexploded; B, exploded; b, barbs; c, the nettling cell in which the nettling…

"Longitudinal section of a Hydra; <em>b</em>, bud which will form a young one; <em>ba</em>, base by which it is attached when not creeping." &mdash; Davison, 1906

Section of a hydra

"Longitudinal section of a Hydra; b, bud which will form a young one; ba, base by…

"Vertical section of the leaf of Potamogeton or Pondweed, showing air cavities or lecunae l, and parenehymatous cells p, with granules." &mdash; Encyclopedia Britanica, 1893

Pondweed Leaf

"Vertical section of the leaf of Potamogeton or Pondweed, showing air cavities or lecunae l, and parenehymatous…

"Portions of sections through the disc of medusae. The upper one of Lizzia, the lower of Aurelia. el, endoderm lamelia, or vascular lamelia; m, muscular processes of the ectoderm cells in cross section; d, ectoderm; en, endoderm lining the enteric cavity; e, wandering endoderm cells of the gelatinous substances." &mdash; Encyclopedia Britannica, 1893

Medusae

"Portions of sections through the disc of medusae. The upper one of Lizzia, the lower of Aurelia. el,…

"A muscle cell from the stomach." &mdash; Ritchie, 1918

Muscle cell

"A muscle cell from the stomach." — Ritchie, 1918

"Muscular cells of medusae (Lizzia). The uppermost is a purely muscular cell from the sub-umbrella; the two lower are epidermo-muscular cells from the base of a tentacle; the upstanding nucloated portion forms part of the epidermal mosaic on the free surface of the body." &mdash; Encyclopedia Britannica, 1893

Muscular Cells

"Muscular cells of medusae (Lizzia). The uppermost is a purely muscular cell from the sub-umbrella;…

The development of muscular fibers from cells. Labels: a, simple cell. b, a pair of cells fused together. c, Three cells fused and their contents assuming the striated character. d, A muscular fiber exhibiting its original composition of cells.

The Development of Muscular Fibers from Cells

The development of muscular fibers from cells. Labels: a, simple cell. b, a pair of cells fused together.…

"Nematocyst of Hydra, showing cell-substance and nucleus, cyat, trigger hair, and everted thread." &mdash; Encyclopedia Britannica, 1893

Nematocyst

"Nematocyst of Hydra, showing cell-substance and nucleus, cyat, trigger hair, and everted thread." —…

"Nerve tissue is really made up of a great number of distinctive units called <em>nerve cells</em>. Each cell usually contains a large nucleus and gives off one or more tiny branches, or processes. Thse cells vary more in shape and size than any other cell in the body. Each nerve cell has a number of short branches, and many have also one long branch which can be traced for some distance from the cell body." — Blaisedell, 1904

Nerve Cells

"Nerve tissue is really made up of a great number of distinctive units called nerve cells.…

"Showing a motor cell with its long, unbranched process (with two little lateral offshoots), with motor endings in striated, voluntary muscular tissue." &mdash; Blaisedell, 1904

Neuron

"Showing a motor cell with its long, unbranched process (with two little lateral offshoots), with motor…

"A nerve cell from the brain." &mdash; Ritchie, 1918

Neuron

"A nerve cell from the brain." — Ritchie, 1918

"Non-striped spindle-shaped cells which branch and join with one another." &mdash; Richardson, 1906

Non-Striated Muscle

"Non-striped spindle-shaped cells which branch and join with one another." — Richardson, 1906

"Ocellus of a medusa (Lizzia Koellikeri). oc, pigmented ectodermal cells; l, lens." &mdash; Encyclopedia Britannica, 1893

Ocellus

"Ocellus of a medusa (Lizzia Koellikeri). oc, pigmented ectodermal cells; l, lens." — Encyclopedia…

The ovum and its coverings. The corona radiata, which completely surrounds the ovum, is only represented in the lower part of the figure. Labels: 1, corona radiate; 2, granular layer; 3, vitelline membrane; 4, zona pellucida (oolemma); 5, vitellus or yolk; 6, germinal vesicle (nucleus); 7, germinal spot (nucleolus); 8, nuclear membrane.

Ovum

The ovum and its coverings. The corona radiata, which completely surrounds the ovum, is only represented…

The diagram of a human ovum, showing the parts of an animal cell.

A Diagram of the Human Ovum

The diagram of a human ovum, showing the parts of an animal cell.

The maturation of the ovum. A, An ovum at the commencement process. B, After the formation of the spindle. The chromosomes are gathered at the equator of the spindle in groups of four, i.e. in tetrads, each which consists of two dyads. C, One apex of the spindle has projected into a bud on the surface, and the dyads have passed to the poles. D, The separation of the first polar body. E, The commencement of the second polar body; F, The completion of the second polar body.

Maturation of the Ovum

The maturation of the ovum. A, An ovum at the commencement process. B, After the formation of the spindle.…

Figure showing battery cells connected in parallel, with all of the positive ends wired together, and all of the negative ends wired together.

Parallel Connection

Figure showing battery cells connected in parallel, with all of the positive ends wired together, and…

"Partz acid gravity cell. In this form of cell, the electrolyte which surrounds the zinc is either magnesium sulphate or common salt. the depolarizer is a bichromate silution which surounds the perforated carbon plate located in the bottom of the jar. A vertical carbon rod fits snugly into the tapered hole in the carbon plate, and extends through the cover forming the positive pole." -Hawkins, 1917

Partz Cell

"Partz acid gravity cell. In this form of cell, the electrolyte which surrounds the zinc is either magnesium…

"Under the power of about 90 diameters the general character of the peridia is seen. They are densely aggregated, elongated, submerged, pale-brown, irregularly torn. The sporidia are copius...Nos. 1 and 2, indicate the general points of growth of this fungus. I find frequently on the leaf-ribs and terminal points of the leaves, and very often dispersed over the smooth parts of the leaf; sometimes, although rarely, the peridia are on the upper surface which, when matured, resembles net work. At the juncture of the leaf (see 4) the cells of the peridia are nearly round, at 5, oblong. From 3 to 4 the cellular structure is of light Vandyke brown; at 5, a pale yellow...6 represents the appearance of the peridia as see by the naked eye; 7, their general arrangements and their groupings on the leaves; 8, three cells, showing the parts of which the peridia are composed being magnified about 125 diameters." -Watts, 1874

Cellular structure of peridia

"Under the power of about 90 diameters the general character of the peridia is seen. They are densely…

"It is not unusual to fine a decayed spot in the center of potatoes otherwise apparently in good condition. A microscopic examination a portion of the diseased part will show that the decay commenced where the vascular bundles concentrate. At that point the air is in greater volume than elsewhere. Although these mineral acids and caustic alkalies dissolve starch granuals, they do not affect the cellulose cells which contain the starch. When such spots are exposed to the atmosphere the fungus blue-mold forms on the surface. This disease, therefore, has not relation to potato-rot, as ordinarily understood. f represents the mycelium (roots) of blue-mold, Penicillium glaucum, and G that of potato-rot, Peronospora infestans." -Watts, 1874

Potato Diseases at a Microscopic Level

"It is not unusual to fine a decayed spot in the center of potatoes otherwise apparently in good condition.…

A genus of single-celled algae often forming a yellowish-green stratum on trees' damp walls, and in shallow pools.

Protococcus

A genus of single-celled algae often forming a yellowish-green stratum on trees' damp walls, and in…

"Splitting of partition wall between guard-cells to form the stoma (Sachs.)" &mdash; Encyclopedia Britanica, 1893

Sachs

"Splitting of partition wall between guard-cells to form the stoma (Sachs.)" — Encyclopedia Britanica,…

"Epidermis of leaf of Saxifraga Sarmentosa, showing clusters of stomata s, surrounded by large epidermal cells e. The cells among which the stomata occus are very small." &mdash; Encyclopedia Britanica, 1893

Saxifraga Sarmentosa

"Epidermis of leaf of Saxifraga Sarmentosa, showing clusters of stomata s, surrounded by large epidermal…

"Development of the lateral eyes of a scorpion. h, Epidermic cell-layer; mes, mesoblastic connective tissue; n, nerves; II, III, IV, V, depressions of the epidermis in each of which a cuticular lens will be formed." &mdash; The Encyclopedia Britannica, 1910

Scorpion Eyes

"Development of the lateral eyes of a scorpion. h, Epidermic cell-layer; mes, mesoblastic connective…

Spermatozooid, mature male germ cells, of <i>Adiantum capillus-veneris</i>. Also called spermatozoid.

Spermatozooid of the Southern Maidenhair Fern and Venus Hair Fern

Spermatozooid, mature male germ cells, of Adiantum capillus-veneris. Also called spermatozoid.

"Spherical cell (resting stage of Amoeba) illustrating general or universal symmetry. Any plane passing through the center will divide it into two essentially equal portions." &mdash; Galloway

Spherical Cell

"Spherical cell (resting stage of Amoeba) illustrating general or universal symmetry. Any plane passing…

"Spirillum containing many spores (a), which are liberated at b by the breaking up of the parent cells." &mdash; The Encyclopedia Britannica, 1910

Spirillum

"Spirillum containing many spores (a), which are liberated at b by the breaking up of the parent cells."…

"Two female sporosacs (degenerate medusae) of Hydraetinia echinata. a, ectoderm; b, endoderm; o, eggcella; g, entric cavity. In A an invagination of the ectoderm, which is more complete in B, represents the rudiment of the sub-umbrella space." &mdash; Encyclopedia Britannica, 1893

Sporosac

"Two female sporosacs (degenerate medusae) of Hydraetinia echinata. a, ectoderm; b, endoderm; o, eggcella;…

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric cavity and its continuations; the lighter shading represents the genital products (ova or sperm). Medualform person still attached by a stalk at the aboral pole to a colony." &mdash; Encyclopedia Britannica, 1893

Sporosae

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric…

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric cavity and its continuations; the lighter shading represents the genital products (ova or sperm). Modified medusiform person, with margin of the disc (umbrella) united above and importforato (mouthless) manubrium." &mdash; Encyclopedia Britannica, 1893

Sporosae

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric…

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric cavity and its continuations; the lighter shading represents the genital products (ova or sperm). Sporosac, with imcomplete extension of the enteric cavity into the umbrella,-rudimentary invagination above to form the sub-umbrella cavity." &mdash; Encyclopedia Britannica, 1893

Sporosae

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric…

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric cavity and its continuations; the lighter shading represents the genital products (ova or sperm). Sporosac with manubrial portion only of the enteric cavity." &mdash; Encyclopedia Britannica, 1893

Sporosae

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric…

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric cavity and its continuations; the lighter shading represents the genital products (ova or sperm). Sporosac without any trace of manubrium." &mdash; Encyclopedia Britannica, 1893

Sporosae

"Gradual degeneration of the medusa bud into the form of a sporosae. The black represents the enteric…

An illustration of corn starch cells.

Corn Starch

An illustration of corn starch cells.

"Simple tentaculocyst of one of the Trachomedusae (Rhopalonema velatum). The process carrying the otolith or concretion hk, formed by endoderm cells, is enclosed by an upgrowth forming the "vesicle," which is not yet quite closed in at the top." &mdash; Encyclopedia Britannica, 1893

Trachomedusae

"Simple tentaculocyst of one of the Trachomedusae (Rhopalonema velatum). The process carrying the otolith…

"Cellular tissue from leaf of Urostigma elasticum. c, a large cell; r, cystolith, an agglomeration of crystals situated at the extremity of an inward prolongation of the cell-wall, t; u, cells filled with chlorophyll granules." &mdash; Encyclopedia Britanica, 1893

Urostigma Elasticum

"Cellular tissue from leaf of Urostigma elasticum. c, a large cell; r, cystolith, an agglomeration of…

"Organisms found upon the Skin o a Grape and concerned in the Fermentation of Wine." &mdash; Blaisedell, 1904

Fermentation of wine

"Organisms found upon the Skin o a Grape and concerned in the Fermentation of Wine." — Blaisedell,…

"Showing a Bit of Common Yeast Cake when mixed with Water and examined under the Microscope. There are large numbers of minute oval bodies, inside of which may commonly be seen one of more smaller bodies knows as <em>vacuoles</em>, shown in <em>a</em> and <em>b</em>. <em>c</em> shows a nucleus, <em>n</em>, inside of the yeast cell; <em>d shows a budding cell with the nucleus dividing; <em>e</em> shows the cell divided, the new cell containing a bit of the old nucleus." &mdash; Blaisedell, 1904

Yeast cake

"Showing a Bit of Common Yeast Cake when mixed with Water and examined under the Microscope. There are…

"Yeast Cells, found in the Juice of Apples, which cause the fermentation of Cider." &mdash; Blaisedell, 1904

Yeast cells

"Yeast Cells, found in the Juice of Apples, which cause the fermentation of Cider." — Blaisedell,…

Growing Yeast Cells, showing Method of budding and forming Groups of Cells. Each bud appears as a little swelling on the side of the larger cell, as seen in <em>a</em> and <em>b</em>. In <em>c</em> the little bud has grown to be nearly as large as the parent cell. The little buds grow one after another, making irregularly shaped groups, as shown in <em>d</em>." &mdash; Blaisedell, 1904

Growing yeast cells

Growing Yeast Cells, showing Method of budding and forming Groups of Cells. Each bud appears as a little…