Marigolds, of the Composite family.

Marigolds

Marigolds, of the Composite family.

An illustration showing how to construct a parabola by plotting. "Having given the axis, vertex, and focus of the parabola. Divide the transverse axis into any desired number of parts 1, 2, 3, etc., and draw ordinates through the divisions; take the distance A1, and set it off on the 1st ordinate from the focus f to a, so that A1 = fa. Repeat the same operation with the other ordinates - that is, set off the distance A5 from f to e, so that A5 = fe; and so the parabola is constructed."

Construction Of A Parabola

An illustration showing how to construct a parabola by plotting. "Having given the axis, vertex, and…

An illustration showing how to construct an ellipse using circle arcs. "Divide the long axis into three equal parts, draw the two circles, and where they intersect one another are the centers for the tangent arcs of the ellipses as shown by the figure."

Construction Of An Ellipse

An illustration showing how to construct an ellipse using circle arcs. "Divide the long axis into three…

An illustration showing how to construct an ellipse using circle arcs. "Given the two axes, set off the short axis from A to b, divide b into three equal parts, set off two of these parts from o towards c and c which are the centers for the ends of the ellipse. Make equilateral triangles on cc, when ee will be the centers for the sides of the ellipse. If the long axis is more than twice the short one, this construction will not make a good ellipse."

Construction Of An Ellipse

An illustration showing how to construct an ellipse using circle arcs. "Given the two axes, set off…

The fruit and leaves of a mulberry tree or Morus.

Mulberry

The fruit and leaves of a mulberry tree or Morus.

An illustration showing how to construct an ellipse. Given the two axes, set off half the long axis from c to ff, which will be the two focuses in the ellipse. Divide the long axis into any number of parts, say a to be a division point. Take Aa as radius and f as center and describe a circle arc about b, take aB as radius and f as center describe another circle arc about b, then the intersection b is a point in the ellipse, and so the whole ellipse can be constructed."

Construction Of An Ellipse

An illustration showing how to construct an ellipse. Given the two axes, set off half the long axis…

An illustration showing how to construct a cycloid. "The circumference C=3.14D. Divide the rolling circle and base line C into a number of equal parts, draw through the division point the ordinates and abscissas, make aa' = 1d, bb' = 2'e, cc = 3f, then ab' and c' are points in the cycloid. In the Epicycloid and Hypocycloid the abscissas are circles and the ordinates are radii to one common center."

Construction Of A Cycloid

An illustration showing how to construct a cycloid. "The circumference C=3.14D. Divide the rolling circle…

An illustration showing how to construct an evolute of a circle. "Given the pitch p, the angle v, and radius r. Divide the angle v into a number of equal parts, draw the radii and tangents for each part, divide the pitch p into an equal number of equal parts, then the first tangent will be one part, second two parts, third three parts, etc., and so the Evolute is traced."

Construction Of An Evolute Of A Circle

An illustration showing how to construct an evolute of a circle. "Given the pitch p, the angle v, and…

An illustration showing how to construct a parabola. "Given the vertex A, axis x, and a point P. Draw AB at right angle to x, and BP parallel to x, divide AB and BP into an equal number of equal parts. From the vertex A draw lines to the divisions on BP, from the divisions on AB draw the ordinates parallel to x, the corresponding intersections are points in the parabola."

Construction Of A Parabola

An illustration showing how to construct a parabola. "Given the vertex A, axis x, and a point P. Draw…

An illustration showing how to construct an arithmetic spiral. "Given the pitch p and angle v, divide them into an equal number of equal parts, say 6; make 01 = 01, 02 = 02, 03 = 03, 04 = 04, 05 = 05, and 06 = the pitch p; then join the points 1, 2, 3, 4, 5 and 6, which will form the spiral required."

Construction Of An Arithmetic Spiral

An illustration showing how to construct an arithmetic spiral. "Given the pitch p and angle v, divide…

A small cruciferous plant, growing in arid Arabia and Palestine. When full grown and ripe its leaves drop and it becomes rolled up like a ball in the dry season, but opens its branches and seed vessels when it comes in contact with moisture.

Illustration of Roots and Jericho Rose

A small cruciferous plant, growing in arid Arabia and Palestine. When full grown and ripe its leaves…

A strong-scented herbaceous plant of the genus Ruta, nat. order Rutacae, a native of S. Europe, but also cultivated in gardens in the United States.

Rue Plant

A strong-scented herbaceous plant of the genus Ruta, nat. order Rutacae, a native of S. Europe, but…

"A pump for exhausting air and other gases from a closed space, or for compressing air within an enclosed space." -Foster, 1921

Air Pump

"A pump for exhausting air and other gases from a closed space, or for compressing air within an enclosed…

The aloe plant is native to Africa and used for its healing properties.

Aloe

The aloe plant is native to Africa and used for its healing properties.

The arrowroot plant, an edible starch.

Arrowroot

The arrowroot plant, an edible starch.

"Bamboo, a giant, treelike member of the grass family." -Foster, 1921

Bamboo

"Bamboo, a giant, treelike member of the grass family." -Foster, 1921

The mistletoe, a parasitic plant more well-known as a Christmas decoration.

Mistletoe

The mistletoe, a parasitic plant more well-known as a Christmas decoration.

The jimson weed (Datura stramonium) of the Nightshade family known as a hallucinogen.

Jimson Weed

The jimson weed (Datura stramonium) of the Nightshade family known as a hallucinogen.

The larkspur (Consolida) is a flowering plant of the buttercup family.

Larkspur

The larkspur (Consolida) is a flowering plant of the buttercup family.

The huckleberry is a fruit of the heath family of plants.

Huckleberry

The huckleberry is a fruit of the heath family of plants.

The cranberry is a fruit of the heath family of plants.

Cranberry

The cranberry is a fruit of the heath family of plants.

The honeysuckle is a flowering plant of the heath family.

Honeysuckle

The honeysuckle is a flowering plant of the heath family.

The rhododendron is a flowering plant of the heath family.

Rhododendron

The rhododendron is a flowering plant of the heath family.

The bleeding heart is a flowering plant of the poppy family.

Bleeding Heart

The bleeding heart is a flowering plant of the poppy family.

A group of insects belonging to the order Hymenoptera, and distinguished by the peculiar confirmation of the ovipositor of the females, which is composed of two broad plates, with serrated or toothed edges.

Saw Fly Hovering Above a Plant

A group of insects belonging to the order Hymenoptera, and distinguished by the peculiar confirmation…

The opium plant can be used to produce sleep, numb pain, and quiet the organs of the body.

Opium Plant

The opium plant can be used to produce sleep, numb pain, and quiet the organs of the body.

The flax plant supplies the thread required for linen manufacturing.

Flax Plant

The flax plant supplies the thread required for linen manufacturing.

In birds the lungs are confined to the back wall of the chest. They are not separated into lobes, but are oblong and flattened in shape, and connected with a series of air-receptacles scattered through various parts of the body. Shown is the right lung of a goose. Labels: 1, A bronchial tube which divides into two tubes that open into the abdominal air-receptacles (2).

The Right Lung of a Goose

In birds the lungs are confined to the back wall of the chest. They are not separated into lobes, but…

In birds the lungs are confined to the back wall of the chest. They are not separated into lobes, but are oblong and flattened in shape, and connected with a series of air-receptacles scattered through various parts of the body. Shown is a section of a bird lung, magnified. Labels: 1, A bronchial tube that ends in a sac (caeca). 2, Division of the bronchial tubes that branch out among lobules. B, A plexus of capillary vessels.

Section of the Lung of a Bird

In birds the lungs are confined to the back wall of the chest. They are not separated into lobes, but…

In the class of Crustacea there is a single ventricle, which receives the blood from the gills and propels it to other parts of the body. Shown is the heart and arteries of a lobster. Labels: 1, The heart. 2, The abdominal artery. 5, Venous sinuses. 6, The branchia from which the blood returns to the hear.

The Heart and Arteries of a Lobster

In the class of Crustacea there is a single ventricle, which receives the blood from the gills and propels…

A longitudinal section of a kidney. Labels: 1, 2, 3, Parts of the Kidney. 4, Pelvis. 5, Ureter. 6, Renal artery. 7, Renal vein. 8, Branches of the latter vessels in the kidney.

Longitudinal Section of a Kidney

A longitudinal section of a kidney. Labels: 1, 2, 3, Parts of the Kidney. 4, Pelvis. 5, Ureter. 6, Renal…

A view of all the parts of the ear, Labels: 1, The tube that leads to the internal ear. 2, The membrana tympani. 3, 4, 5, The bones of the ear. 7, The central part of the labyrinth, names the vestibule. 8, 9, 10, The semicircular canals. 11, 12, The channels of the cochlea. 13, The auditory nerve. 14, The channel from the middle ear to the throat (Eustachian tube). 15, A nerve. 16, A process. 17, The seventh pair of nerves (facial). 18, A process of the temporal bone.

Parts of the Ear

A view of all the parts of the ear, Labels: 1, The tube that leads to the internal ear. 2, The membrana…

"The principal working parts of the apparatus are the sheet of boiler plate a (fig. 100), the cylinder c, the piston head p, the screw s, and conduit plate d...f, frame." -Walcott, 1901

Intrusion Machine

"The principal working parts of the apparatus are the sheet of boiler plate a (fig. 100), the cylinder…

"Leaf of a willow (Salix sp.). b, blade; p, petiole; s, stipules." -Gager, 1916

Willow Leaf

"Leaf of a willow (Salix sp.). b, blade; p, petiole; s, stipules." -Gager, 1916

"Diagram to show the essential parts of a "flowering" plant. t.r., tap-root; cot. seed-leaf (cotyledon); i, internode; a.l, leaf-axil; n, node; a.b, axillary buud; r, receptacle of floral organs; ca, calyx; per, perianth; co, corolla; st, stamens (androecium); pi, pistil (gynoecium)." -Gager, 1916

Flower Parts

"Diagram to show the essential parts of a "flowering" plant. t.r., tap-root; cot. seed-leaf (cotyledon);…

"Tulip bulb; longitudinal section. F, solid stem; B, flower bud; S, leaf-bases serving as bud-scales, and also for the storage of plant food." -Gager, 1916

Tulip Bulb

"Tulip bulb; longitudinal section. F, solid stem; B, flower bud; S, leaf-bases serving as bud-scales,…

"Leaf of a live-forever (Sedum sp.), with a portion of the epidermis peeled back. Underneath the epidermis is the mesophyll." -Gager, 1916

Sedum Leaf

"Leaf of a live-forever (Sedum sp.), with a portion of the epidermis peeled back. Underneath the epidermis…

"Mullein (Verbascum Thapsus). L, cross-section of leaf-blade, showing relative thickness of a layer of epidermal hairs; H, a single hair from a leaf." -Gager, 1916

Mullein Leaf

"Mullein (Verbascum Thapsus). L, cross-section of leaf-blade, showing relative thickness of a layer…

"Lizard's tail (Saururus cernuus). Portions of leaf-epidermis; U, upper epidermis; L, lower epidermis; ep, epidermal cell; st, guard-cells of the stomata." -Gager, 1916

Leaf Epidermis

"Lizard's tail (Saururus cernuus). Portions of leaf-epidermis; U, upper epidermis; L, lower epidermis;…

"Cross-sections of leaves of an oak (Quercus novimexicana), showing the effect of different light conditions on the internal anatomy. 1, from leaf growing in sunlight; 2, from leaf growing in the shade." -Gager, 1916

Oak Leaf Cross-Section

"Cross-sections of leaves of an oak (Quercus novimexicana), showing the effect of different light conditions…

"Horse-chestnut (Aesculus Hippocastanum). ls, leaf-scar, showing scars of seven fibro-vascular bundles, corresponding, in number, to the seven leaflets of the compound leaf, formerly attached at ls. The leaf is drawn to a smaller scale than the branch." -Gager, 1916

Horse-Chestnut Leaf

"Horse-chestnut (Aesculus Hippocastanum). ls, leaf-scar, showing scars of seven fibro-vascular bundles,…

"Roots of the water-hyacinth (Eichornia crassipes Solms), showing removable root-caps; b, root-cap removed from c." -Gager, 1916

Water Hyacinth Roots

"Roots of the water-hyacinth (Eichornia crassipes Solms), showing removable root-caps; b, root-cap removed…

"Diagram to illustrate a root-hair (h) in the soil, and its relation to the soil-particles, the capillary film of water (w), and the air spaces (a); e, epidermal cell of the root, of which the root-hair is an out-growth, or branch." -Gager, 1916

Roots in Soil

"Diagram to illustrate a root-hair (h) in the soil, and its relation to the soil-particles, the capillary…

"Diagram showing tissue-systems in young stem of castor-oil plant (Ricinus communis), as seen in cross-section. ep, epidermis; cor, cortex; p, pith or medulla; b, fibro-vascular bundle; ph, phloem; ca, cambium; x, xylem; ic, interfascicular cambium." -Gager, 1916

Castor-Oil Plant Stem

"Diagram showing tissue-systems in young stem of castor-oil plant (Ricinus communis), as seen in cross-section.…

"The castor-oil plant (Ricinus communis). Portion of cross-section of young stem. co, Cortex; p, pith or medulla; e, epidermis; ph, phloem; ca, cambium; x, xylem. The last three elements compose the fibro-vascular bundle, the cambium being continuous from bundle to bundle; the portion between the bundles is called interfascicular cambium." -Gager, 1916

Castor-Oil Plant Stem

"The castor-oil plant (Ricinus communis). Portion of cross-section of young stem. co, Cortex; p, pith…

"Cell of Pellionia Daveauana, showing starch-grains. The black, crescent-shaped body on the end of each grain is the amyloplast." -Gager, 1916

Pellionia Plant Cell

"Cell of Pellionia Daveauana, showing starch-grains. The black, crescent-shaped body on the end of each…

"Portion of dandelion scape, showing "curls" resulting from longitudinal tissue-tension." -Gager, 1916

Dandelion Scape

"Portion of dandelion scape, showing "curls" resulting from longitudinal tissue-tension." -Gager, 1916

"Knight's experiment, substituting centrifugal "force" for gravity" proved that stems do not grow upwards because of sunlight but rather, roots grow downwards because of gravity. -Gager, 1916

Knight's Experiment

"Knight's experiment, substituting centrifugal "force" for gravity" proved that stems do not grow upwards…

"Effect of removal of a leaflet from a palmately compound leaf (e.g. Woodbine). B, normal leaf; C, after removal of upper right-hand leaflet. A, Unbroken lines represent average normal position of leaflets; dotted lines, average position of leaflets after operation; barred line, position of leaflet removed." -Gager, 1916

Leaflet Removal

"Effect of removal of a leaflet from a palmately compound leaf (e.g. Woodbine). B, normal leaf; C, after…

"A, Upper epidermis; B, lower epidermis, of the fern, Drynaria meyeniana." -Gager, 1916

Fern Epidermis

"A, Upper epidermis; B, lower epidermis, of the fern, Drynaria meyeniana." -Gager, 1916

"Germination of the spores of a fern. a, Before germination; b, early stage, showing protonema (pr.), and first rhizoid (rh); c, d, e, f, successive stages in the development of the prothallus." -Gager, 1916

Fern Germination

"Germination of the spores of a fern. a, Before germination; b, early stage, showing protonema (pr.),…

"Fern prothallus; cross-sections showing antheridia (an), sperms (sp), and rhizoids (rh). Below at the right is a sperm (sp) greatly enlarged." -Gager, 1916

Fern Prothallus

"Fern prothallus; cross-sections showing antheridia (an), sperms (sp), and rhizoids (rh). Below at the…

"Adder's tongue fern (Ophioglossum vulgatum L.). R, runner or stolon." -Gager, 1916

Southern Adderstongue

"Adder's tongue fern (Ophioglossum vulgatum L.). R, runner or stolon." -Gager, 1916

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.

A, A young vegetable cell, showing cell cavity entirely filled with granular protoplasm enclosing a large oval nucleus with one or more nucleoli. B, An older cells from the same plant showing distinct cellulose wall and vacuolation of protoplasm.

Vegetable Cell

A, A young vegetable cell, showing cell cavity entirely filled with granular protoplasm enclosing a…

Flat, pigmented, branched connective tissue cells from the sheath of a large blood vessel of a frog's mesentery. The pigment is not distributed uniformly throughout the substance of the larger cell, consequently some parts of it look blacker than others (uncontracted state). In the two smaller cells most of the pigment is withdrawn into the cell body, so that they appear smaller, blacker, and less branched.

Connective Tissue Cells from a Frog

Flat, pigmented, branched connective tissue cells from the sheath of a large blood vessel of a frog's…

Part of section of developing tooth of a young rat, showing the mode of deposition of the dentine. Labels: a, outer layer of fully formed dentine; b, uncalcified matrix with one or two nodules of calcareous matter near the calcified parts; c, odontoblasts sending processes into the dentine; d, pulp; e, fusiform or wedge-shape cells found between odontoblasts; f, stellate cells of pulp in fibrous connective tissue. The section is stained in carmine, which colors the uncalcified matrix, but not the calcified part.

Deposition of Dentine

Part of section of developing tooth of a young rat, showing the mode of deposition of the dentine. Labels:…

Muscular fiber torn across; the sarcolemma still connecting the two parts of the fiber.

Torn Muscular Fiber

Muscular fiber torn across; the sarcolemma still connecting the two parts of the fiber.

Sarcostyles from the wing muscle of a wasp. A, A'. A sarcostyles showing degrees of retraction. B. A sarcostyle extended with the sarcous element separated into two parts. C. Sarcostyles moderately extended.

Sarcostyles from Wasp

Sarcostyles from the wing muscle of a wasp. A, A'. A sarcostyles showing degrees of retraction. B. A…

The form of the capillary network presents considerable variety in the different textures of the body: the varieties consists principally of modifications of two chief kind of mesh, the rounded and the elongated. The kind in which the meshes or interspaces have a roundish form is the most common, and prevails in those parts which the capillary network is most dense, such as the lungs. Shown is the network of capillary vessels of the air cells of the horse's lung magnified. Labels: a, capillaries proceeding from b, terminal branched of the pulmonary artery.

Capillary Vessels of Air Cells

The form of the capillary network presents considerable variety in the different textures of the body:…