ClipArt ETC
"Stone cells from different sources. 1, from coffee; 2, 3, and 4, from stem of clove; 5 and 6, from tea leaf; 7, 8, and 9, from powdered star anise seed." -Stevens, 1916

Stone Cells

"Stone cells from different sources. 1, from coffee; 2, 3, and 4, from stem of clove; 5 and 6, from…

"Camera-lucida outline of portion of cross section of cornstalk, showing at g bast fiber zone beneath the epidermis and surrounding the outermost vascular bundles." -Stevens, 1916

Cornstalk Bast Fibers

"Camera-lucida outline of portion of cross section of cornstalk, showing at g bast fiber zone beneath…

"Cross section of a portion of palm stem. e, xylem; f, phloem portions of vascular bundle; g, sclerenchyma tissue about vascular bundle; d, fundamental or ground tissue; c, larger tracheal tubes in vascular bundle." -Stevens, 1916

Palm Stem

"Cross section of a portion of palm stem. e, xylem; f, phloem portions of vascular bundle; g, sclerenchyma…

"Diagram showing the progressive development of the skeletal tissues from the apex toward the base of the stem." -Stevens, 1916

Plant Skeletal Tissues

"Diagram showing the progressive development of the skeletal tissues from the apex toward the base of…

"Cross section of a root in the region of the root hairs." -Stevens, 1916

Plant Root Hairs

"Cross section of a root in the region of the root hairs." -Stevens, 1916

"Apex of root hair flattened out over and imbedding soil particles." -Stevens, 1916

Plant Root Hair

"Apex of root hair flattened out over and imbedding soil particles." -Stevens, 1916

"A single root hair on a large scale, showing that it is an outgrowth of an epidermal cell, and the fact that it possesses a living protoplast and large vacuole filled with cell-sap and traversed by cytoplasmic strands. The nucleus is near the apex of the hair." -Stevens, 1916

Plant Root Hair

"A single root hair on a large scale, showing that it is an outgrowth of an epidermal cell, and the…

"Portion of cross section through an aerial root of Stanhopea oculata. h, the velamen; i, exodermis; j, cortex; k, endodermis." -Stevens, 1916

S. Oculata Aerial Root

"Portion of cross section through an aerial root of Stanhopea oculata. h, the velamen; i, exodermis;…

"Showing at f the felty body covering the passage way through the exodermis of the aerial root of Sobralia macrantha." -Stevens, 1916

S. Macrantha Aerial Root

"Showing at f the felty body covering the passage way through the exodermis of the aerial root of Sobralia…

"Cross section through a water-absorbing scale of Tillandsia usneoides; a, a, water-absorbing cells partially filled with water." -Stevens, 1916

T. Usneoides Cell

"Cross section through a water-absorbing scale of Tillandsia usneoides; a, a, water-absorbing cells…

"A, diagram of course of vascular bundles in a palm stem; 1m, 2m, 3m, bundles from the median portions of the leaves." -Stevens, 1916

Palm Stem

"A, diagram of course of vascular bundles in a palm stem; 1m, 2m, 3m, bundles from the median portions…

"B, diagram of vascular bundles in external view and in cross section of the stem of Cerastium. The leaves are shown cut off at 1, 2, 2' and 3." -Stevens, 1916

Cerastium Stem

"B, diagram of vascular bundles in external view and in cross section of the stem of Cerastium. The…

"Diagram showing the course of the vascular bundles in a stem of Clematis viticella. Median bundles from the leaves are marked A, lateral bundles B and C." -Stevens, 1916

C. Viticella Stem

"Diagram showing the course of the vascular bundles in a stem of Clematis viticella. Median bundles…

"Different stages in the development of a bordered pit. b, The original, thin, primary wall; a, the overhanging border formed as the wall thickened. B, Thickening of the wall has continued and extended the border; the primary wall has thickened at c, forming the torus. C, the border and the torus are finished." -Stevens, 1916

Pit Development

"Different stages in the development of a bordered pit. b, The original, thin, primary wall; a, the…

"Diagrammatic representation of a block of pine wood highly magnified. a, Early growth; b, late growth; c, intercellular space; d, bordered pit in tangential wall of late growth; m, f and e, bordered pit in radial wall of early growth from different points of view; h, row of medullary cells for carrying food; g, row of medullary ray cells for carrying water; k, thin place in radial wall of ray cells that carry food." -Stevens, 1916

Magnified Pine

"Diagrammatic representation of a block of pine wood highly magnified. a, Early growth; b, late growth;…

"Diagram to show the tangential flow of water from the side where there is less demand to the side where the demand is greater." -Stevens, 1916

Water Flow in Plants

"Diagram to show the tangential flow of water from the side where there is less demand to the side where…

"Diagram showing by the arrows how the water can flow tangentially around a plant without traversing the medullary rays, which are indicated in black." -Stevens, 1916

Water Flow in Plants

"Diagram showing by the arrows how the water can flow tangentially around a plant without traversing…

"Diagram to show the radial flow of water in pine wood, from the tracheids of the late growth of one year into those of early growth of the succeeding year." -Stevens, 1916

Water Flow in Pine

"Diagram to show the radial flow of water in pine wood, from the tracheids of the late growth of one…

"Diagram indicating by arrows how the water in the tracheids of pine passes longitudinally from one tracheid to another." -Stevens, 1916

Water Flow in Pine

"Diagram indicating by arrows how the water in the tracheids of pine passes longitudinally from one…

"Diagram showing the relation of the water-carrying tissues of the leaves to those of the stem, and how the older rings of growth give up their water to the newer before this water can enter the leaves. The figures at the bottom indicate in years the age of the rings." -Stevens, 1916

Water Flow in Plants

"Diagram showing the relation of the water-carrying tissues of the leaves to those of the stem, and…

A: "Camera-lucida drawing of a bleached leaf of a Dicotyledon, showing the course of the vascular bundles, and how end free in the mesophyll." C:magnified detail. -Stevens, 1916

Dicotyledon Leaf

A: "Camera-lucida drawing of a bleached leaf of a Dicotyledon, showing the course of the vascular bundles,…

B: "Camera-lucida drawing of a bleached leaf of... a Monocotyledon, showing the anastomosis of the parallel veins by means of slender lateral branches." D: magnified detail. -Stevens, 1916

Monocotyledon Leaf

B: "Camera-lucida drawing of a bleached leaf of... a Monocotyledon, showing the anastomosis of the parallel…

"Semi-diagrammatic cross section of a leaf showing by arrows how the water passes from the tracheal elements of a vein into the border parenchyma cells, and thence into the palisade and spongy parenchyma, from which it evaporates into the intercellular spaces and passes from the leaf through the stomata. a, upper epidermis; b, lower epidermis; c, palisade parenchyma; g, spongy parenchyma; d, border parenchyma; e, tracheal elements; and the stippled cells bellow e, the phloem cells." -Stevens, 1916

Leaf Water Flow

"Semi-diagrammatic cross section of a leaf showing by arrows how the water passes from the tracheal…

"Diagram to show the path of the water as it rises to, and escapes from, the leaves." -Stevens, 1916

Leaf Water Flow

"Diagram to show the path of the water as it rises to, and escapes from, the leaves." -Stevens, 1916

The cross section of the stem of hop, which carries large amounts of water.

Hop Stem Tissue

The cross section of the stem of hop, which carries large amounts of water.

The cross section of the stem of yellow poplar, which carries large amounts of water.

Yellow Poplar Stem Tissue

The cross section of the stem of yellow poplar, which carries large amounts of water.

The cross section of the stem of water cress, which carries very little water.

Water Cress Stem Tissue

The cross section of the stem of water cress, which carries very little water.

The cross section of the stem of Pisdium Galapageium, which carries very little water.

P. Galapageium Stem Tissue

The cross section of the stem of Pisdium Galapageium, which carries very little water.

"A typical stoma in cross section and surface view combined. k, guard cell; j, the gap or stoma between the guard cells; l, epidermal cell bordering a guard cell." -Stevens, 1916

Stoma

"A typical stoma in cross section and surface view combined. k, guard cell; j, the gap or stoma between…

"A, diagram showing relative position of the guard cells in cross section in the open and closed positions; the heavier line indicates the open position." -Stevens, 1916

Stoma Guard Cells

"A, diagram showing relative position of the guard cells in cross section in the open and closed positions;…

"B and C, early stages in the formation of stomata; at s, mother cells of guard cells are shown. D, s, s, two guard cells formed by the division of a mother cell." -Stevens, 1916

Stomata Formation

"B and C, early stages in the formation of stomata; at s, mother cells of guard cells are shown. D,…

"Diagram of apparatus showing how the guard cells draw apart; j, j, position of the rubber tubing when the water pressure is turned on." -Stevens, 1916

Guard Cell Experiment

"Diagram of apparatus showing how the guard cells draw apart; j, j, position of the rubber tubing when…

"A, depressed stoma of the under side of a leaf of Amherstia nobilis." -Stevens, 1916

Depressed Stoma

"A, depressed stoma of the under side of a leaf of Amherstia nobilis." -Stevens, 1916

"B, depressed stoma of Hakea suaveolens. g stands beneath the guard cells; d, outer, and e inner, cavities." -Stevens, 1916

Depressed Stoma

"B, depressed stoma of Hakea suaveolens. g stands beneath the guard cells; d, outer, and e inner, cavities."…

"Diagram suggestive of the distribution of intercellular spaces throughout a plant. The heavy horizontal lines in stem and root indicate intercellular spaces in medullary rays. The arrows indicate the entrance of gasses through the stomata of the leaves and stomata and lenticels of the roots and everywhere over the younger roots where waterproofing is slight." -Stevens, 1916

Intercellular Spaces of a Plant

"Diagram suggestive of the distribution of intercellular spaces throughout a plant. The heavy horizontal…

"A, cross section of stem of Juncus...the black lines traversing the section are really chains of cells and thin-walled cells with relatively large intercellular spaces between them fill up i." -Stevens, 1916

Juncus Stem

"A, cross section of stem of Juncus...the black lines traversing the section are really chains of cells…

"B, stem of Nymphaea, showing large intercellular spaces at i." -Stevens, 1916

Nymphaea Stem

"B, stem of Nymphaea, showing large intercellular spaces at i." -Stevens, 1916

"Cross section of a portion of the blade of a leaf, showing upper epidermis at a, lower epidermis at b, palisade parenchyma at c, spongy parenchyma at d, and tracheids from the end of a vein at e." -Stevens, 1916

Leaf Epidermis

"Cross section of a portion of the blade of a leaf, showing upper epidermis at a, lower epidermis at…

"Diagrammatic representation of a single palisade cell, with chloroplasts lining the walls." -Stevens, 1916

Palisade Cell

"Diagrammatic representation of a single palisade cell, with chloroplasts lining the walls." -Stevens,…

"Starch grains from the palisade cells of a Euphorbia leaf." -Stevens, 1916

Euphorbia Palisade Cells

"Starch grains from the palisade cells of a Euphorbia leaf." -Stevens, 1916

"Diagram to show the intake of carbon dioxide by the palisade cells from the intercellular spaces, the absorption by the chloroplasts of water from the cell-sap, and the passage of food from the chloroplasts into the cell-sap." -Stevens, 1916

Palisade Cell Intake

"Diagram to show the intake of carbon dioxide by the palisade cells from the intercellular spaces, the…

"Diagram showing how the position of the chlorplasts against the vertical walls of the palisade cells exposes them to good advantage to light from all quarters of the sky." -Stevens, 1916

Plant Light Intake

"Diagram showing how the position of the chlorplasts against the vertical walls of the palisade cells…

"Diagram to show the activities going on in a palisade cell. The arrows from the chloroplasts into the cell cavity indicate movement of photosynthesized product. The thickness of the arrow shafts under "Light" indicate the relative light intensities." -Stevens, 1916

Palisade Cell

"Diagram to show the activities going on in a palisade cell. The arrows from the chloroplasts into the…

"Diagram to show the effect of different portions of the spectrum on photosynthesis. a to F, different regions of the spectrum from red to blue. A filamentous alga lies across these, and bacteria are collecting about the alga, with greatest frequency in the red between B and C, indicating the greatest evolution of oxygen there." -Stevens, 1916

Photosynthesis

"Diagram to show the effect of different portions of the spectrum on photosynthesis. a to F, different…

"Diagram to show the three general tissue regions of a leaf." -Stevens, 1916

Leaf Tissues

"Diagram to show the three general tissue regions of a leaf." -Stevens, 1916

"Showing intercellular spaces: f, between the palisade cells; e, in a leaf; g, border parenchyma; h, tracheal elements of the vein." -Stevens, 1916

Intercellular Spaces of Leaf

"Showing intercellular spaces: f, between the palisade cells; e, in a leaf; g, border parenchyma; h,…

"Diagram to show the architecture of a typical leaf in the region of one of the lateral veins. The shaded parts amongst the palisade and spongy parenchyma represent intercellular spaces." -Stevens, 1916

Leaf Architecture

"Diagram to show the architecture of a typical leaf in the region of one of the lateral veins. The shaded…

"Cross section through a portion of rubber leaf, showing the large percentage of water-storage tissues on both sides of the leaf, and the relation of the palisade and spongy parenchyma to the lateral veins." -Stevens, 1916

Rubber Leaf Cells

"Cross section through a portion of rubber leaf, showing the large percentage of water-storage tissues…

"Cross section of a portion of a leaf of Indian corn. a, upper and b, lower epidermis; c, c, palisade cells; n, border parenchyma containing starch within its chloroplasts; e, vascular bundle; d, d, stomata." -Stevens, 1916

Indian Corn Leaf Cells

"Cross section of a portion of a leaf of Indian corn. a, upper and b, lower epidermis; c, c, palisade…

"Cross section of a portion of leaf of Codonanthe, showing the water-storage tissue at f, and the chlorophyll-bearing tissues at e." -Stevens, 1916

Codonanthe Leaf Tissues

"Cross section of a portion of leaf of Codonanthe, showing the water-storage tissue at f, and the chlorophyll-bearing…

"A, Pleurococcus, with chloroplast at c." -Stevens, 1916

Pleurococcus Chloroplast

"A, Pleurococcus, with chloroplast at c." -Stevens, 1916

"B, cell of Spirogyra, with spiral chloroplast at c, nucleus at n, and pyrenoid at e." -Stevens, 1916

Spirogyra Chloroplast

"B, cell of Spirogyra, with spiral chloroplast at c, nucleus at n, and pyrenoid at e." -Stevens, 1916

"C, cross section of Spirogyra cell, with nucleus at n, and section of chloroplast and pyrenoid below." -Stevens, 1916

Spirogyra Chloroplast

"C, cross section of Spirogyra cell, with nucleus at n, and section of chloroplast and pyrenoid below."…

"D, cell of Oedogonium, with numerous chloroplasts." -Stevens, 1916

Oedogonium Chloroplast

"D, cell of Oedogonium, with numerous chloroplasts." -Stevens, 1916

"Cross section through the thallus of Marchantia. j, stoma leading into a relatively large air-chamber in which arise numerous cells with chloroplasts, k; l, l, cells forming partitions between the air-chambers; m, cells destitute of chloroplasts and with numerous oblong pits; h, upper, and i, lower epidermis." -Stevens, 1916

Marchantia Thallus

"Cross section through the thallus of Marchantia. j, stoma leading into a relatively large air-chamber…

"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,…

"Diagram to show path of stored food upward through the tracheal tubes, and through the phloem portion of the bark, and showing how this passage is not prevented by girdling." -Stevens, 1916

Stored Food

"Diagram to show path of stored food upward through the tracheal tubes, and through the phloem portion…

"Showing pitted connections between medullary rays and xylem parenchyma, and between contiguous xylem parenchyma cells. m, medullary rays; n, xylem parenchyma. Camera-lucida drawing of tangential section of wood of yellow poplar." -Stevens, 1916

Yellow Poplar Wood

"Showing pitted connections between medullary rays and xylem parenchyma, and between contiguous xylem…