ClipArt ETC
"Portion of leaf of Sphagnum, in cross section on the left, and surface view on the right. h, hole through the wall; i, chlorophyll-bearing cells; j, water-storage and water-conducting cells, with annular thickenings at k." -Stevens, 1916

Sphagnum Leaf

"Portion of leaf of Sphagnum, in cross section on the left, and surface view on the right. h, hole through…

"Cross section through a portion of leaf of Polytrichum commune. b, chains of chlorophyll-bearing cells; d, bast fibers." -Stevens, 1916

P. Commune Leaf

"Cross section through a portion of leaf of Polytrichum commune. b, chains of chlorophyll-bearing cells;…

"Cross section, A, and surface view, B, of a leaf of common moss, showing chloroplasts, c." -Stevens, 1916

Moss Leaf Chloroplasts

"Cross section, A, and surface view, B, of a leaf of common moss, showing chloroplasts, c." -Stevens,…

"Cross section of leaf of Mesembryanthemum Forskalii showing a large part of the leaf devoted to the storage of water. a, water-storage cells; b, chlorophyll-bearing cells; c, crystal of calcium oxalate." -Stevens, 1916

M. Forskalli Leaf

"Cross section of leaf of Mesembryanthemum Forskalii showing a large part of the leaf devoted to the…

"Portion of a cross section through a nectariferous bract of Vicia sepium; n, nectar-secreting cells." -Stevens, 1916

V. Sepium Bract

"Portion of a cross section through a nectariferous bract of Vicia sepium; n, nectar-secreting cells."…

"Cross section through a portion of orange peel showing the cavity of an interior, globular gland at g; crystals of hesperidin at h; calcium oxalate crystals at k." -Stevens, 1916

Orange Peel Glands

"Cross section through a portion of orange peel showing the cavity of an interior, globular gland at…

"Schizogenous resin duct in the young stem of ivy (Hedera helix), as seen in cross section. A, early, and B, later stage in the formation of the duct. g, the mature duct; c, cambium wb, phloem; b, bast fibers." -Stevens, 1916

Ivy Stem

"Schizogenous resin duct in the young stem of ivy (Hedera helix), as seen in cross section. A, early,…

"Resin duct in leaf of Pinus silvestris, in cross section at A, and in longitudinal section at B; h, cavity surrounded by the secreting cells; f, f, sclerenchyma fibers surrounding and protecting the duct." -Stevens, 1916

Leaf Resin Duct

"Resin duct in leaf of Pinus silvestris, in cross section at A, and in longitudinal section at B; h,…

"Glands from Pinguicula. A, upper surface of leaf showing long-stalked gland at m, and short-stalked gland at n. B, cross section through a short-stalked gland." -Stevens, 1916

Leaf Glands

"Glands from Pinguicula. A, upper surface of leaf showing long-stalked gland at m, and short-stalked…

"One-celled hydatode of Gonocaryum pyriforme, seen in cross section at A, and from the surface in B." -Stevens, 1916

G. Pyriforme Hydatode

"One-celled hydatode of Gonocaryum pyriforme, seen in cross section at A, and from the surface in B."…

"Section of a Limestone Cavern...A limestone hill, perforated by a cavern (b b) which communicates with the valley (v) by an opening (a). The bottom of the cavern is covered with ossiferous loam, above which lies a layer of stalagmite (d d), while stalactites hang from the roof, and by joining the floor separate the cavern into two chambers." -Geikie, 1893

Limestone Cavern

"Section of a Limestone Cavern...A limestone hill, perforated by a cavern (b b) which communicates with…

"Section of a Limestone Cavern with fallen-in roof and concealed entrance." -Geikie, 1893

Limestone Cavern

"Section of a Limestone Cavern with fallen-in roof and concealed entrance." -Geikie, 1893

The cross section of a river.

River Cross Section

The cross section of a river.

"By downward corrasion a stream cuts a steep-sided trench of its own width, but weathering, gravitation, and the wash of the rain widen it and make the sides sloping." a, a young V-shaped valley; b and c, deeper; d, flood-plain condition. -Dryer, 1901

Valley Development

"By downward corrasion a stream cuts a steep-sided trench of its own width, but weathering, gravitation,…

"If the walls of the valley contain strata of unequal hardness, the form is modified by the projection of hard layers and the retreat of the softer ones." -Dryer, 1901

Unequal Valley Development

"If the walls of the valley contain strata of unequal hardness, the form is modified by the projection…

"If the strata are not horizontal, various unsymmetrical forms are produced." -Dryer, 1901

Usymmetrical Valley Development

"If the strata are not horizontal, various unsymmetrical forms are produced." -Dryer, 1901

Cross section of an eroded anticline.

Eroded Anticline

Cross section of an eroded anticline.

Cross section of an eroded syncline.

Eroded Syncline

Cross section of an eroded syncline.

The cross section of a mature anther lobe in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Anther Lobe

The cross section of a mature anther lobe in the stages of "formation of anthers and pollen grains or…

The cross section of a mature anther lobe in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Anther Lobe

The cross section of a mature anther lobe in the stages of "formation of anthers and pollen grains or…

"A, small mound of earth thrown up by the queen when starting her formicary; x, entrance; z, first chamber; A', same nest in section." -National Geographic, 1912

Ant-Hill Stage 1

"A, small mound of earth thrown up by the queen when starting her formicary; x, entrance; z, first chamber;…

"C, dome of adult colony; C', section of same showing galleries and chambers used for incubation of the young." -National Geographic, 1912

Ant-Hill Stage 3

"C, dome of adult colony; C', section of same showing galleries and chambers used for incubation of…

Of the milkwort family (Polygalaceae), the cross-leaved milkwort or Polygala cruciata.

Cross-Leaved Milkwort

Of the milkwort family (Polygalaceae), the cross-leaved milkwort or Polygala cruciata.

Of the St. John's Wort family (Hypericaceae), St. Andrew's Cross or Ascyrum hypericoides.

St. Andrew's Cross

Of the St. John's Wort family (Hypericaceae), St. Andrew's Cross or Ascyrum hypericoides.

This image "represents a cross section through the ejector with the magazine loaded. The parts shown are receiver, A; bolt, B; firing pin, C; ejector, D; clip slots, E; bolt locking lug channels, F; magazine, G; follower, H; magazine spring, I; and floor plate, J." -Moss, 1914

Loaded Magazine

This image "represents a cross section through the ejector with the magazine loaded. The parts shown…

This image "shows a cross section through the magazine empty, and with cut-off "on," shown in projection. The parts are receiver, A; bolt, B; firing pin, C; cut-off, D; rear lug slot, E; bolt locking lug channels, F; magazine, G; follower, H; magazine spring, I; and floor plate, J." -Moss, 1914

Empty Magazine

This image "shows a cross section through the magazine empty, and with cut-off "on," shown in projection.…

"Determination of the optical character of a uniaxial crystal with the gypsum plate when the center of the cross is beyond the field of the microscope. Quartz (+)." -Johannsen, 1908

Gypsum Plate

"Determination of the optical character of a uniaxial crystal with the gypsum plate when the center…

"Cross-sections at right angles to both (001) and (010) showing (+) and (-) character of extinction in plagioclase feldspars." -Johannsen, 1908

Plagioclase Feldspars

"Cross-sections at right angles to both (001) and (010) showing (+) and (-) character of extinction…

"Diagram showing types of canal system. --After Korschelt and Heider. The flagellate regions are dark throughout, the mesogloea is dotted, the arrows show the direction of the currents. All the figures represent cross-sections through the wall. A. Simple Ascon type (Ec., outer layer; En., inner layer; Mg., mesogloea). B. Sycon type, with flagellage radial chambers (r.c.). CC. Leucon type, with flagellate side aisles on the main radial chambers. D. Still more complex type, with small flagellate chambers (f.ch.)." -Thomson, 1916

Sponge Canal System

"Diagram showing types of canal system. --After Korschelt and Heider. The flagellate regions are dark…

"Structure of Antipatharians. 1. A group of polyps--M. mouth; t., tentacles. 2. Axis without polyps and coenenchyma, covered with spines (Sp.). 3. Vertical section of polyp--A., axis; t., tentacle; g., gullet; m., mesentery; o., ovary; m.f., mesenteric filaments. 4. Cross section of a polyp--EC., ectoderm; M., mesogloea; EN., endoderm; G., gullet; MS., mesenteries." -Thomson, 1916

Antipatharians

"Structure of Antipatharians. 1. A group of polyps--M. mouth; t., tentacles. 2. Axis without polyps…

"Cross-section through Ascaris. d.n., Dorsal nerve; n.c., non-contractile portion of muscle cells; c., cuticle; e., epidermis; l.l., lateral line; e.v., excretory vessel; m., contractile portion of muscle cells; v.n., ventral nerve; ov., ovary; ut., uterus; g., gut." -Thomson, 1916

Ascaris

"Cross-section through Ascaris. d.n., Dorsal nerve; n.c., non-contractile portion of muscle cells; c.,…

"Cross-section of Arenicola. E., Epidermis; c.m., circular muscles; l.m., longitudinal muscles; b.c., body cavity; gl., gill; s., setae; n.p., nephridial pore; a.br., afferent branchial; e.br., efferent branchial; n., ventral nerve-cord, with blood vessels above; d.v., dorsal vessel; l.v., lateral vessel; s.i.v., sub-intestinal vessels; v.v., ventral vessel; g., gut." -Thomson, 1916

Arenicola

"Cross-section of Arenicola. E., Epidermis; c.m., circular muscles; l.m., longitudinal muscles; b.c.,…

"Diagrammatic cross-section of starfish arm. n., Radial nerve; b.v., radial blood vessel according to Ludwig, septum in pseud-haemal vessel according to others; w.v., radial water vessel; am., ampulla; t.f., tube-foot; p.c., a pyloric caecum cut across; s.p., a calcareous spine; g., a skin-gill; lac., spaces in the wall; go., ova in ovary; a.o., ambulacral ossicle." -Thomson, 1916

Starfish Arm

"Diagrammatic cross-section of starfish arm. n., Radial nerve; b.v., radial blood vessel according to…

"Vertical cross-section of a Trilobite (Calymene). i., Intestine; s., shield; L., endopodite; e., exopodite; b., epipodial parts." -Thomson, 1916

Trilobite

"Vertical cross-section of a Trilobite (Calymene). i., Intestine; s., shield; L., endopodite; e., exopodite;…

"Bony Tissue. A, portion of cross-section of a bone, the upper portion of the figure representing the outer surface of the bone, just beneath the periosteum. The open spaces, h, are Haversian canals; l, lacunae, occupied in life by bone cells. The minute canals through the bone connecting the lacunae are canaliculi. B, a portion of one Haversian system much magnified. h, Haversian anal, containing arter (a), vein (v), lymphatic spaces, nutritive cells; c, canaliculi; l, lacunae; la, plae of bone intercellular substance." -Galloway, 1915

Bony Tissue

"Bony Tissue. A, portion of cross-section of a bone, the upper portion of the figure representing the…

"Diagram of a cross-section of the spinal cord through the roots of spinal nerves. c, central canal; d.f., dorsal fissure; d.r., dorsal root of spinal nerve arising from the dorsal horn of the gray matter (g); gn., ganglion on the dorsal root; n, spinal nerve; v.f., ventral fissure; v.r., ventral root of the spinal nerve, arising from the ventral horn of the gray matter; w., white matter." -Galloway, 1915

Spinal Cord

"Diagram of a cross-section of the spinal cord through the roots of spinal nerves. c, central canal;…

"Terraced Hills, Glen Colombkill." -Taylor, 1904

Terraced Hills

"Terraced Hills, Glen Colombkill." -Taylor, 1904

"Terraced Hills of the Burren, as seen from the north of Galway Bay." -Taylor, 1904

Terraced Hills

"Terraced Hills of the Burren, as seen from the north of Galway Bay." -Taylor, 1904

"Diagrammatic cross-section of stem of Indian corn. cv, fibro-vascular bundles; gc, pithy material between bundles." -Bergen, 1896

Corn Section

"Diagrammatic cross-section of stem of Indian corn. cv, fibro-vascular bundles; gc, pithy material between…

Plan of the body in cross-section. The systems in the body are arranged in a certain way which is the same in all animals which have a backbone. The plan of the bony skeleton is a central axis from which all other parts are extended. In this lies the central axis of the nervous system, from which its branches also extend.

Diagram of the Body Plan

Plan of the body in cross-section. The systems in the body are arranged in a certain way which is the…

"Common Pitcher-Plant (Sarracenia purpurea). At the right one of the pitcher-like leaves is shown in cross-section." -Bergen, 1896

Common Pitcher Plant

"Common Pitcher-Plant (Sarracenia purpurea). At the right one of the pitcher-like leaves is shown in…

"Cross-section of an orange. a, axis of fruit with dots showing cut-off ends of fibro-vascular bundles; p, partition between cells of ovary; S, seed; c, cell of ovary filled with a pulp composed of irregular tubes full of juice; o, oil reservoirs near outer surface of rind; e, corky layer of epidermis." -Bergen, 1896

Orange

"Cross-section of an orange. a, axis of fruit with dots showing cut-off ends of fibro-vascular bundles;…

"Begonia Flowers. A, staminate flower; B, pistillate flower; C, twisted stigmas, enlarged; D, cross-section of ovary; o, ovary; s, sepals; p, petals." -Bergen, 1896

Begonia

"Begonia Flowers. A, staminate flower; B, pistillate flower; C, twisted stigmas, enlarged; D, cross-section…

"Flower and fruit of Umbelliferae. A, flower of Foeniculum; B, fruit of Heracleum; C, fruit of Heracleum, cross-section; o (in A), ovary; d, disk; sg, stigma; s, stamens; o (in B, and C), oil-tubes; r, ribs. A, B, and C all enlarged." -Bergen, 1896

Umbelliferae

"Flower and fruit of Umbelliferae. A, flower of Foeniculum; B, fruit of Heracleum; C, fruit of Heracleum,…

"Cardamom. a, cross section of fruit; b, fruit; c, flower; d, seeds." -Foster, 1921

Cardamom

"Cardamom. a, cross section of fruit; b, fruit; c, flower; d, seeds." -Foster, 1921

Dressed in scarlet, and carrying the banner of the expedition, Columbus landed. He was followed by a priest with a cross and the men of the ships. All knelt upon the sandy shore and thanked God for his goodness. Then Columbus took possession of the land in the name of the sovereigns of Spain, Ferdinand and Isabella.

Columbus Discovering Land

Dressed in scarlet, and carrying the banner of the expedition, Columbus landed. He was followed by a…

An illustration showing the construction used to erect a perpendicular from a point to a line. "With C as a center, draw the dotted circle arc so that it cuts the line at A and B. With A and B as centers, draw the dotted cross arcs at D with equal radii. Draw the required perpendicular through C and crossing D."

Construction Of A Perpendicular

An illustration showing the construction used to erect a perpendicular from a point to a line. "With…

An illustration showing the construction used to erect a parallel line. "With C as a center, draw the dotted arc ED, with E as a center, draw through C the dotted arc F.C. With the radius FC and E as a center, draw the cross arc at D. Join C with the cross at D, which will be the required parallel line.

Construction Of A Parallel

An illustration showing the construction used to erect a parallel line. "With C as a center, draw the…

An illustration showing the construction used to divide an angle into two equal parts. "With C as a center, draw the dotted arc DE; with D and E as centers, draw the cross arcs at F with equal radii. Join CF, which divides the angle into the required parts."

Construction Of A Divided Angle

An illustration showing the construction used to divide an angle into two equal parts. "With C as a…

An illustration showing the construction used to divide an angle into two equal parts when the lines do not extend to a meeting point. "Draw the lined CD and CE parallel, and at equal distances from the lines AB and FG. With C as a center, draw the dotted arc BG; and with B and G as centers, draw the cross arcs H. Join CD, which divides the angle into the required equal parts."

Construction Of A Divided Angle

An illustration showing the construction used to divide an angle into two equal parts when the lines…

An illustration showing the construction used to erect a parallelogram given two sides and an angle. "Draw the base line DE, and make the angle FDE = C; lines DE = B and DF = A; complete the parallelogram by cross arcs at G, and the problem is thus solved."

Construction Of A Parallelogram

An illustration showing the construction used to erect a parallelogram given two sides and an angle.…

An illustration showing how to find the center of a circle which will pass through three given points A, B, and C. "With B as a center, draw the arc DEFG; and with the same radius and A as a center, draw the cross arcs D and F; also with C as a center, draw the cross arcs E and G. Join D and F, and also E and G, and the crossing o is the required center of the circle."

Find The Center Of A Circle Through 3 Points

An illustration showing how to find the center of a circle which will pass through three given points…

An illustration showing how to construct a tangent to a circle through a given point in a circumference. "Through a given point A and center C, draw the line BC. With A as a center, draw the circle arcs B and C; with B and C as centers, draw the cross arcs D and E; then join D and E, which is the required tangent."

Construction Of Tangent To Circle

An illustration showing how to construct a tangent to a circle through a given point in a circumference.…

An illustration showing how to construct the center and radius of a circle that will tangent a given circle and line. "From C, erect the perpendicular CG; set off the given radius r from C to H. With H as a center and r as radius, draw the cross arcs on the circle. Through the cross arcs draw the line IG; then G is the center of the circle arc FIC, which tangents the line at C and the circle at F."

Construction Of A Center And Radius Of A Circle That Will Tangent A Given Circle And Line

An illustration showing how to construct the center and radius of a circle that will tangent a given…

An illustration showing how to construct a square circumscribed about a circle. "Draw the diameters AB and CD at right angles to one another; with the radius of the circle, and A, B, C, and D as centers, draw the four dotted half circles which cross one another in the corners of the square, and thus complete the problem."

Construction Of A Square Circumscribed About A Circle

An illustration showing how to construct a square circumscribed about a circle. "Draw the diameters…

An illustration showing how to construct a pentagon on a given line. "From B erect BC perpendicular to and half the length of AB; join A and C prolonged to D; with C as center and CB as radius, draw the arc BD; then the chord BB is the radius of the circle circumscribing the pentagon. With A and B as centers, and BD as radius, draw the cross O in the center."

Construction Of A Pentagon On A Line

An illustration showing how to construct a pentagon on a given line. "From B erect BC perpendicular…

An illustration showing how to construct a pentagon on a given line without resort to its center. "From B erect Bo perpendicular to and equal to AB; with C as center and Co as radius, draw the arc Do, then AD is the diagonal of the pentagon. With AD as radius and A as center, draw the arc DE; and with E as center and AB as radius, finish the cross E, and thus complete the pentagon."

Construction Of A Pentagon On A Line

An illustration showing how to construct a pentagon on a given line without resort to its center. "From…

An illustration showing how to construct a hyperbola by plotting. "Having given the transverse axis BC, vertexes Aa, and foci ff'. Set off any desired number of parts on the axis below the focus, and number them 1,2,3,4,,5,etc. Take the distance a1 as radius, and, with f' as center, strike the cross 1 with f'1=a1. With the distance A1, and the focus f as center, strike the cross 1 with the radius F1=A1, and the cross 1 is a point in the hyperbola."

Construction Of A Hyperbola

An illustration showing how to construct a hyperbola by plotting. "Having given the transverse axis…

An illustration showing a quadrilateral model that illustrates the following relationships: a:b = c:d, ad = bc, A = B. Product of the means equals the product of the extremes.

Model Of Geometric Proportions

An illustration showing a quadrilateral model that illustrates the following relationships: a:b = c:d,…

An illustration showing a model that illustrates the following relationships: a:b = c:d, ad = bc. Product of the means equals the product of the extremes.

Model Of Geometric Proportions

An illustration showing a model that illustrates the following relationships: a:b = c:d, ad = bc. Product…