"Diagram showing how the vascular bundles anastomose around the medullary rays. The gaps represent the rays." -Stevens, 1916

Vascular Bundles

"Diagram showing how the vascular bundles anastomose around the medullary rays. The gaps represent the…

Types of vascular bundles: "A, the concentric type, with xylem, k, surrounding the phloem, h." -Stevens, 1916

Concentric Vascular Bundle

Types of vascular bundles: "A, the concentric type, with xylem, k, surrounding the phloem, h." -Stevens,…

Types of vascular bundles: "B, the collateral type, with phloem, h, standing in front of the xylem, k." -Stevens, 1916

Collateral Vascular Bundle

Types of vascular bundles: "B, the collateral type, with phloem, h, standing in front of the xylem,…

Types of vascular bundles: "C, a portion of the radial type, shown complete in D, where the part outlined at a, corresponds to C. Corresponding parts are lettered the same in both figures; c, xylem; b, phloem; f, cambium ring; e, pericycle; d, endodermis. C and D are from the tap root of Vicia faba." -Stevens, 1916

Radial Vascular Bundle

Types of vascular bundles: "C, a portion of the radial type, shown complete in D, where the part outlined…

"Gleichenia pubescens: transverse section of stem, showing the protostele." -Stevens, 1916

G. Pubescens Stem

"Gleichenia pubescens: transverse section of stem, showing the protostele." -Stevens, 1916

"Adianium pedatum: transverse section of stem, showing the amphiphloic siphonostele." -Stevens, 1916

A. Pedaium Stem

"Adianium pedatum: transverse section of stem, showing the amphiphloic siphonostele." -Stevens, 1916

"Pteris aquilina: transverse section of stem, showing the polystele." -Stevens, 1916

P. Aquilina Stem

"Pteris aquilina: transverse section of stem, showing the polystele." -Stevens, 1916

"Diagram showing additions to the primary tissues through the activity of the cambium and phellogen or cork cambium." -Stevens, 1916

Plant Tissues

"Diagram showing additions to the primary tissues through the activity of the cambium and phellogen…

"Diagram showing the relation of this year's leaves to the wood of the current year." -Stevens, 1916

Plant Tissues

"Diagram showing the relation of this year's leaves to the wood of the current year." -Stevens, 1916

"Portion of a cross section throughout the stem of Dracaena marginata. P, parenchyma of cortex. V, meristematic zone of the pericycle by the activity of which the stem increases in diameter, with the addition of new vascular bundles. M, mature vascular bundle. N, nearly mature vascular bundle. O, newly formed procambium strand from which a vascular bundle is to arise. B, beginning of a procambium strand by the division of cells in the meristematic zone. F, parenchyma of the fundamental tissue." -Stevens, 1916

D. Marginata Stem

"Portion of a cross section throughout the stem of Dracaena marginata. P, parenchyma of cortex. V, meristematic…

"Diagram showing some types of unusual growth in thickness. A, cross section through a four-year-old stem of Anisostichus capreolata." -Stevens, 1916

A. Capreolata Unusual Stem Growth

"Diagram showing some types of unusual growth in thickness. A, cross section through a four-year-old…

"Diagram showing some types of unusual growth in thickness...B, cross section of stem of species of Bauhinia; the xylem strands, b, are stippled while the surrounding parenchyma and bark tissues are left white." -Stevens, 1916

Bauhinia Unusual Stem Growth

"Diagram showing some types of unusual growth in thickness...B, cross section of stem of species of…

"Diagram showing some types of unusual growth in thickness...C, portion of a cross section of stem of Gnetum scandens; 1, 2, and 3 are successive rings of growth; m, is the pith; b, is a sclerenchyma ring. The xylem portions with the exception of the larger tracheal tubes are shaded, while the medullary rays, phloem and tissues intervening between the rings of growth and the outer cortes tissues are left white." -Stevens, 1916

G. Scandens Unusual Stem Growth

"Diagram showing some types of unusual growth in thickness...C, portion of a cross section of stem of…

"A, cross section through upper half of leaf of Pyrus Japonica, showing cutinized layer of the outer wall at f, and cellulose layer at g." -Stevens, 1916

P. Japonica Epidermis

"A, cross section through upper half of leaf of Pyrus Japonica, showing cutinized layer of the outer…

A cross section through the upper half of a Russian olive leaf, showing a "cutinized layer of the outer wall at f, and cellulose layer at g." -Stevens, 1916

Russian Olive Leaf Epidermis

A cross section through the upper half of a Russian olive leaf, showing a "cutinized layer of the outer…

"C, portion of cross section of submerged stem of Nymphaea odorata, where there is no cutinized layer, and the cuticle is a hardly distinguishable film." -Stevens, 1916

N. Odorata Epidermis

"C, portion of cross section of submerged stem of Nymphaea odorata, where there is no cutinized layer,…

"A, portion of cross section of leaf of Avicennia growing in salty soil; outer wall of epidermis very thick." -Stevens, 1916

Avicennia Epidermis

"A, portion of cross section of leaf of Avicennia growing in salty soil; outer wall of epidermis very…

"B, cross section through skin of apple." -Stevens, 1916

Apple Epidermis

"B, cross section through skin of apple." -Stevens, 1916

"C, cross section through upper half of petal of Japan Quince." -Stevens, 1916

Japan Quince Epidermis

"C, cross section through upper half of petal of Japan Quince." -Stevens, 1916

"D, upper, and E, lower epidermis of leaf of Hibiscus moscheutos." -Stevens, 1916

H. Moscheutos Epidermis

"D, upper, and E, lower epidermis of leaf of Hibiscus moscheutos." -Stevens, 1916

"Different forms of epidermal outgrowths. 1, hooked hair from Phaseolus multiflorus; 2, climbing hair from stem of Humulus Lupulus; 3, rod-like wax coating from the stem of Saccharum offininarum; 4, climbing hair of Lossa hispida; 5, stinging hair of Urtica urens." -Stevens, 1916

Epidermal Outgrowths

"Different forms of epidermal outgrowths. 1, hooked hair from Phaseolus multiflorus; 2, climbing hair…

"Multiple epidermis of leaf of mangrove in cross section. This serves as a water reservoir, and the relatively thick walls of the inner cells reenforce the protective power of the outer layer." -Stevens, 1916

Multiple Epidermis

"Multiple epidermis of leaf of mangrove in cross section. This serves as a water reservoir, and the…

"Cross section of yellow poplar wood. E, early; L, late growth; m, medullary ray." -Stevens, 1916

Yellow Poplar Wood

"Cross section of yellow poplar wood. E, early; L, late growth; m, medullary ray." -Stevens, 1916

"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;…

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…