ClipArt ETC
Upper part of a stem of a Horsetail, Equisetum sylvaticum.

Horsetail

Upper part of a stem of a Horsetail, Equisetum sylvaticum.

Part of the head or spike of spore-cases, with some of the latter taken off.

Spore-Cases

Part of the head or spike of spore-cases, with some of the latter taken off.

A Tree-Fern, Dicksonia arborescens, with a young one near its base. In front a common herbaceous Fern (Polypodium vulgare) with its creeping stem or rootstock.

Tree-Fern

A Tree-Fern, Dicksonia arborescens, with a young one near its base. In front a common herbaceous Fern…

A section of the trunk of a Tree-Fern.

Tree-Fern Trunk

A section of the trunk of a Tree-Fern.

A small piece (pinnule) of a Shield-Fern: a row of fruit-dots on each side of the midrib, each covered by its kidney shaped indusium.

Shield-Fern

A small piece (pinnule) of a Shield-Fern: a row of fruit-dots on each side of the midrib, each covered…

Magnified section through a fertile conceptacle of Rockweed, showing the large spores in the midst of threads of cells.

Fertile Conceptacle of Rockweed

Magnified section through a fertile conceptacle of Rockweed, showing the large spores in the midst of…

Section through a conceptacle of Delesseria Leprieurei, showing the spores, which are single specialized cells, two or three in a row.

Delesseria Lepriuerei

Section through a conceptacle of Delesseria Leprieurei, showing the spores, which are single specialized…

This painting was done by Frans Hals. It is an important piece from the military collection by the artist. The piece was painted in 1633.

Banquet of the Officers of the Civic Guard

This painting was done by Frans Hals. It is an important piece from the military collection by the artist.…

Diagram of flower of Trillium. In this, as in all such diagrams of cross-section of blossoms, the parts of the outer circle represent the calyx; the next, corolla; within, stames (here in two circles of three each, and the cross-section is through the anthers); in the centre, section of three ovaries joined into a compound one of three cells.

Trillium

Diagram of flower of Trillium. In this, as in all such diagrams of cross-section of blossoms, the parts…

Diagram of the lower part of an anther, cut across above, and the upper part of a leaf, to show how the one answers to the other; the filament to petiole, the connective to midrib; the two cells to the right and left halves of the blade.

Anther

Diagram of the lower part of an anther, cut across above, and the upper part of a leaf, to show how…

Cells of young root of a seedling Maple.

Maple

Cells of young root of a seedling Maple.

Magnified wood-cells of the bark (bast-cells) of Basswood, one and part of another.

Basswood

Magnified wood-cells of the bark (bast-cells) of Basswood, one and part of another.

Magnified wood-cells of the bark (bast-cells) of Basswood, one and part of another.

Basswood

Magnified wood-cells of the bark (bast-cells) of Basswood, one and part of another.

Some wood-cells from Buttonwood, Platanus, a whole cell and lower end of another on the left; a cell cut half away lengthwise, and half of another on the right; some pores or pits (a) seen on the left; while <em>b b</em> mark sections through these on the cut surface. When lving and young the protoplasm extends into these and by minuter perforations connects across them. In age the pits become open passages, facilitating the passage of sap and air.

Buttonwood

Some wood-cells from Buttonwood, Platanus, a whole cell and lower end of another on the left; a cell…

Milk Vessels of Dandelion, with cells of the common cellular tissue.

Dandelion

Milk Vessels of Dandelion, with cells of the common cellular tissue.

Milk Vessels of Dandelion, with cells of the common cellular tissue.

Dandelion

Milk Vessels of Dandelion, with cells of the common cellular tissue.

Top of a leaf, cut across; it consists of a single layer of cells.

Leaf

Top of a leaf, cut across; it consists of a single layer of cells.

Outlines of a portion of the stem in section, showing the central cell and the outer or cortical cells.

Chara

Outlines of a portion of the stem in section, showing the central cell and the outer or cortical cells.

A piece of the rose-red Delesseria Lepreiurei, showing that it is composed of a layer of cells.

Delesseria Lepreiurei

A piece of the rose-red Delesseria Lepreiurei, showing that it is composed of a layer of cells.

A piece of the rose-red Delesseria Lepreiurei, showing the cells are gelatinous and thick-walled.

Delesseria Lepreiurei

A piece of the rose-red Delesseria Lepreiurei, showing the cells are gelatinous and thick-walled.

Minute portion of a section of a gill, showing some spore-bearing cells.

Mushroom

Minute portion of a section of a gill, showing some spore-bearing cells.

Pithy gall on blackberry, section to show cells.

Pithy Gall

Pithy gall on blackberry, section to show cells.

Burrow of Andrena, showing cells in order of completion; the first at <em>a</em>, the last at <em>f</em>, in which an egg has just been laid.

Andrena

Burrow of Andrena, showing cells in order of completion; the first at a, the last at f,…

A square divided into equal squares, like a chessboard, in each of which is placed one of a series of consecutive numbers from 1 up to the square of the number of cells in a side, in such a manner that the sum of the numbers in each row or column and in each diagonal is constant.

Magic Square

A square divided into equal squares, like a chessboard, in each of which is placed one of a series of…

The magic circle of circles, first developed by Benjamin Franklin, consists of eight annular rings and a central circle, each ring being divided into eight cells by radii drawn from the centre; there are therefore 65 cells. The number 12 is placed in he center and the consecutive numbers 13 to 75 are placed in the other cells. The properties are: 1) sum of eight numbers in any ring with 2 equals 360, 2) sum of eight numbers in any set of radial rings with 12 is 360, 3) sum of numbers in any four adjoining cells is 180.

Magic Circle of Circles

The magic circle of circles, first developed by Benjamin Franklin, consists of eight annular rings and…

Fiber-cells of plain muscular tissue, highly magnified.

Muscle Fiber Cells

Fiber-cells of plain muscular tissue, highly magnified.

Section of the internal saphenous nerve. Stained in osmic acid and subsequently hardened in alcohol. Drawn as seen under a very low magnifying power. Labels: ep, epineurium (general sheath of the nerve consisting of connective tissue separated by cleft-like areolae, which appear as a network of clear lines, with here and there fat-cells), f, f, and blood-vessels, v; per, perineurium (particular sheath of funiculus); end, endoneurium, or connective tissue within funiculus, embedded in which are seen the cut ends of the medullated nerve fibers. The fat cells and the nerve fibers are darkly stained by the osmic acid.

Section of the Internal Saphenous Nerve

Section of the internal saphenous nerve. Stained in osmic acid and subsequently hardened in alcohol.…

Diagram showing the relation of the cerebrospinal to the sympathetic neurons. Labels: A, a medullated fiber, axon, or dendrite, coming from cerebrospinal system and dividing into numerous branches on reaching a sympathetic ganglion. These branches connect with those of the cells, b, B, in the ganglion, and these cells send their non-medullated fibers, axons, or dendrites, to supply the viscera, C, C, C, C.

Diagram of the Relation between Cerebrospinal and Sympathetic Neurons

Diagram showing the relation of the cerebrospinal to the sympathetic neurons. Labels: A, a medullated…

Red and white corpuscles (cells) of the blood, magnified. Labels: A, moderately magnified, the red corpuscles are seen in rouleaux; a, a, white corpuscles; B, C, D, red corpuscles, highly magnified, seen in different positions; E, a red corpuscle swollen in to a sphere by absorption of water; F, G, white corpuscles, highly magnified; K, white corpuscle treated with acetic acid; H, I, red corpuscles wrinkled or crenated.

Red and White Blood Cells

Red and white corpuscles (cells) of the blood, magnified. Labels: A, moderately magnified, the red corpuscles…

Isolated capillary network formed by the junction of several hallowed-out cells, and containing colored blood-corpuscles in a clear fluid. Labels: p, p, pointed cell-processes extending in different directions for union with neighboring capillaries.

Capillary Network

Isolated capillary network formed by the junction of several hallowed-out cells, and containing colored…

Diagram showing various forms of secreting glands. Labels: 1, general plan of a secreating membrane; a, epithelial cells; b, basement membrane; c, connective tissue in which lie the blood-vessels (d); 2-7, simple and compound tubular and saccular glands; d, duct.

Diagram Showing Various Forms of Secreting Glands

Diagram showing various forms of secreting glands. Labels: 1, general plan of a secreating membrane;…

Diagram of two hepatic lobules of the liver. "The left hand lobule is represented with the intralobular vein cut across; in the right hand one the section takes the course of the intralobular vein. p, interlobular branches of the portal vein; h, intralobular branches of the hepatic veins; s, sublobular vein; c, capillaries of the lobules. The arrows indicate the direction of the course of the blood. The liver cells are only represented in one part of each lobule." &mdash; Kimber, 1907.

Hepatic Lobules of the Liver

Diagram of two hepatic lobules of the liver. "The left hand lobule is represented with the intralobular…

Plan of the blood vessels connected with the tubules. "The blood passes downwards in straight vessels between the uriniferous tubules, to be returned by more or less straight veins to the venous arches, whence it is conveyed by large branches into the renal vein, which leaves the kidney at the hilus and pours its contents into the inferior vena cava... Urine is secreted from the blood in two ways. It is partly removed by a process of transudation or filtration, and partly by the secretary action of the cells lining the uriniferous tubules." &mdash;Kimber, 1907.

Plan of the Blood Vessels Connected with the Tubules

Plan of the blood vessels connected with the tubules. "The blood passes downwards in straight vessels…

Section of epidermis. Labels: H, horny layer, consisting of s, superficial horny scales; sw, swollen-out horny cells; s.l., clear layer; M, Malpighian layer, consisting of s.gr. granular layer; p, many-sided or prickle cells; c, columnar cells. Nerve fibrils may be traced passing up between the epithelium cells of the Malpighian layer.

Section of Epidermis (Skin)

Section of epidermis. Labels: H, horny layer, consisting of s, superficial horny scales; sw, swollen-out…

"Diagram of a multiple or parallel connection. When connected in this manner the voltage of the battery is the same as that of a single cell, but the current is equal to the amperage of a single cell multiplied by the number of cells." -Hawkins, 1917

Parallel Connection

"Diagram of a multiple or parallel connection. When connected in this manner the voltage of the battery…

"Diagram of a series multiple connction. Two sets of cells are connected in series, and the two batteries thus formed, connected in parallel. The pressure equals the voltage of one cell, multiplied by the number of cells in one battery, and the amperage, that of one cell multiplied by the number of batteries." -Hawkins, 1917

Series Multiple Connection

"Diagram of a series multiple connction. Two sets of cells are connected in series, and the two batteries…

Diagram showing relations of the neurons and sensory epithelium in the retina. labels: E, epithelial layer of nucleated rode and cone cells, rods being directed towards choroid coat of retina; N1, neurons of first series receiving by their dendritic impulses from the rod and cone cells and transmitting them by their axons to N2, the neurons of the second series. The axons of the neurons of the second series pass along the inner surface of the retina to the blind spot, where they unite to form the optic nerve.

Neurons and Sensory Epithelium in the Retina

Diagram showing relations of the neurons and sensory epithelium in the retina. labels: E, epithelial…

Section of stratified epithelium. Labels: c, lowermost columnar cells; P, polygonal cells above these; fl, flattened cells near the surface. Between the cells are seen intercellular channels, bridged over by processes which pass from cell to cell.

Epithelium Cells

Section of stratified epithelium. Labels: c, lowermost columnar cells; P, polygonal cells above these;…

Section of the transitional epithelium lining the bladder, highly magnified. Labels: a, superficial; b, intermediate; c, deep layer of cells.

Epithelium Cells Lining the Bladder

Section of the transitional epithelium lining the bladder, highly magnified. Labels: a, superficial;…

Simple pavement epithelium. Labels: a, from a serious membrane; b, from a blood vessel. "In simple pavement epithelium, the cells form flat, many-sided plates or scales, which fit together like tiles of a mosaic pavement. It forms very smooth surfaces, and it lines the alveoli of the lungs, the heart, blood vessels, land lymphatics; the mammary ducts, the serous cavities, etc."&mdash;Kimber, 1907.

Simple Pavement Epithelium Cells

Simple pavement epithelium. Labels: a, from a serious membrane; b, from a blood vessel. "In simple pavement…

Simple columnar epithelium. Labels: a, the cells; b, intercellular substance between the lower end of cells. "The columnar epithelium is a variety of simple epithelium in which the cells have a prismatic shape, and are set upright on the surface which they cover. It is found in its most characteristic form lining the mucous membrane of the intestinal canal."&mdash;Kimber, 1907

Simple Columnar Epithelium

Simple columnar epithelium. Labels: a, the cells; b, intercellular substance between the lower end of…

Glandular epithelium with the cells set round a simple saccular gland, highly magnified. "Glandular epithelium is found in the recesses of secreting glands. The cells are of many different shapes, and are usually set round a tubular or saccular cavity, into which the secretion is poured." &mdash;Kimber, 1907

Glandular Epithelium Cells

Glandular epithelium with the cells set round a simple saccular gland, highly magnified. "Glandular…

Ciliated epithelium from the human trachea, highly magnified. Labels: a, large ciliated cell; d, cell, with two nuclei. "In ciliated epithelium the cells, which are generally columnar in shape, bear at their free extremities little hair-like processes which are agitated incessantly with a lashing or vibrating motion. These minute and delicate processes are named cilia, and may be regarded as active prolongations of the cell-protoplasm." &mdash;Kimber, 1907

Ciliated Epithelium Cells

Ciliated epithelium from the human trachea, highly magnified. Labels: a, large ciliated cell; d, cell,…

Subcutaneous areolar tissue from a young rabbit, highly magnified. The white fibers are in wavy bundles, the elastic fibers form an open network. Labels: p, p, vacuolated cells; g, granular cells; c, c, branching lamellar cells; c', a flattened cells, of which only the nucleus and some scattered granules are visible; f, fibrillated cell. "If we make a cut through the skin of some part of the body where there is no subcutaneous fat, as in the upper eyelid, and proceed to raise it from the parts lying beneath, we observe that it is loosely connected to them by a soft filmy substance of considerable tenacity and elasticity. This is areolar tissue. It is also found, in like manner, under the serous and mucous membranes, and serves to attach them to the parts which they line or cover. Proceeding further, we find this areolar tissue lying between the muscles, the blood-vessels, and other deep-seated parts; also forming investing sheaths for the muscles, the nerves, the blood-vessels, and other parts. It both connects and insulates entire organs, and, in addition, performs the same office for the finer parts of which these organs are made up. It is thus one of the most general and most extensively distributed of the tissues." &mdash;Kimber, 1907

Subcutaneous Areolar Tissue from a Young Rabbit

Subcutaneous areolar tissue from a young rabbit, highly magnified. The white fibers are in wavy bundles,…

A few cat cells from the margin of a fat lobule in adipose tissue, very highly magnified. Labels: f.g. fat globules distending a fat cell; n, nucleus; m, membranous envelope of the fat cell; c, capillary vessel; v, veinlet; c.t. connective tissue cell; the fibers of the connective tissue are not shown.

Fat Cells

A few cat cells from the margin of a fat lobule in adipose tissue, very highly magnified. Labels: f.g.…

Transverse section of compact tissue of humerus, magnified about 150 diameters. Three of the Haversian canals are seen, with their concentric rings faintly indicated; also the lacunae, with the canaliculi extending from them across the direction of the encircling lamellae, or concentric rings.

Bone Tissue of Humerus

Transverse section of compact tissue of humerus, magnified about 150 diameters. Three of the Haversian…

"The term battery is applied either to a single jar, or cell, containing the generating materials, or to a number of such cells conected togehter by electric conductors; the latter being the more proper use of the term, though the former use is common." -Atkinson 1903

Battery

"The term battery is applied either to a single jar, or cell, containing the generating materials, or…

"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…

Figure showing a series type of connection between multiple battery cells, where the negative end of one battery is attached to the positive end of the next.

Series Connection

Figure showing a series type of connection between multiple battery cells, where the negative end of…

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…

Forms of cells from the body, showing their various shapes.

Forms of Cells

Forms of cells from the body, showing their various shapes.

Flat cells from the surface of the lining membrane of the abdomen (peritoneum). Labels: a, cell-body; b, nucleus; c, nucleoli.

Cells from the Abdominal Lining

Flat cells from the surface of the lining membrane of the abdomen (peritoneum). Labels: a, cell-body;…

A thin slice of cartilage highly magnified, showing the cartilage cells (a,b) scattered through an almost structureless material.

Cartilage Tissue

A thin slice of cartilage highly magnified, showing the cartilage cells (a,b) scattered through an almost…

"When several cells are conected so that the positive plate of one is joined to the negative plate of the next...they are said to be grouped or joined in series." -Avery 1895

Series Connection

"When several cells are conected so that the positive plate of one is joined to the negative plate of…

"When all of the positive plates are connected on one side, and all of the negative plates are connected on the other side, as shown, the cells are said to be joined in parallel, or in multiple arc." -Avery 1895

Parallel Connection

"When all of the positive plates are connected on one side, and all of the negative plates are connected…

"An electric bell consists mainly of an electromagnet, E, and a vibrating armature that carries a hammer, H, that strikes a bell. One terminal of the magnet coils is connected to the binding-post, and the other terminal to the flexible support of the armature. The armature carries a spring that rests lightly against the tip of an adjustable screw at C. This screw is connected to the other binding-post. The bell is connected to a battery of 2 or 3 cells in series, a key, a push-button, P, or some other device for closing the circuit being placed in the line." -Avery 1895

Electric Bell

"An electric bell consists mainly of an electromagnet, E, and a vibrating armature that carries a hammer,…

Unstriped muscle cells, highly magnified.

Muscle Cells

Unstriped muscle cells, highly magnified.

Muscle fibers from the heart showing the striations and the junctions of the cells, highly magnified.

Muscle Fibers

Muscle fibers from the heart showing the striations and the junctions of the cells, highly magnified.

Cells of a raw potato, with starch grains in natural condition.

Potato Cells

Cells of a raw potato, with starch grains in natural condition.

Blood corpuscles. Labels: A, magnified about 400 diameters. The red corpuscles have arranged themselves in rouleaux; a, a, colorless corpuscles; B, red corpuscles more magnified and seen in focus; E, a red corpuscle slightly out of focus. Near the right-hand top corner is a red corpuscle seen in three-quarter face, and at C one seen edgewise. F,G,kH,I, white corpuscles highly magnified.

Blood Cells

Blood corpuscles. Labels: A, magnified about 400 diameters. The red corpuscles have arranged themselves…