ClipArt ETC
"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, 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…

The epidermis of an oak leaf.

Plant Epidermis

The epidermis of an oak leaf.

The epidermis of an iris leaf.

Plant Epidermis

The epidermis of an iris leaf.

"Group of cells from petal of Viola tricolor." -Stevens, 1916

Plant Epidermis

"Group of cells from petal of Viola tricolor." -Stevens, 1916

"Two epidermal cells in cross section showing thickened outer wall differentiated into three layers, namely, an outer cuticle, cutinized layer (shaded), and an inner cellulose layer." -Stevens, 1916

Plant Epidermis

"Two epidermal cells in cross section showing thickened outer wall differentiated into three layers,…

"Epidermal outgrowths in the form of scales and hairs." -Stevens, 1916

Plant Epidermis

"Epidermal outgrowths in the form of scales and hairs." -Stevens, 1916

"Epidermal outgrowths in the form of scales and hairs." -Stevens, 1916

Plant Epidermis

"Epidermal outgrowths in the form of scales and hairs." -Stevens, 1916

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…

"A, B, C, D, Successive stages of growth of prothallium from the spore in Osmunda cinnamomea; E, growth of fern plant from fertilized egg within the prothallium of Osmunda Claytoniana." -Stevens, 1916

Fern Growth

"A, B, C, D, Successive stages of growth of prothallium from the spore in Osmunda cinnamomea; E, growth…

"A, Antheridium containing sperm cells; B, archegonium containing an egg cell which has been found by five sperm cells. All from Osmunda cinnamomea." -Stevens, 1916

Fern Reproduction

"A, Antheridium containing sperm cells; B, archegonium containing an egg cell which has been found by…

"Diagram showing how, in Indian corn, the food from the upper and lower leaves finds its way into the ears." -Stevens, 1916

Indian Corn Food Circulation

"Diagram showing how, in Indian corn, the food from the upper and lower leaves finds its way into the…

"Diagram illustrating the descent of food from the leaf into the stem, and its circulation upward and downward through the sieve tubes, and upward through the tracheal tissues." -Stevens, 1916

Leaf Food Circulation

"Diagram illustrating the descent of food from the leaf into the stem, and its circulation upward and…

"The digestion of the stored food and its ascent through the tracheal tubes when growth is resumed in the spring." -Stevens, 1916

Plant Food Digestion

"The digestion of the stored food and its ascent through the tracheal tubes when growth is resumed in…

"Diagram to show food from the leaves descending through the sieve tubes and being stored in the medullary ray cells and xylem parenchyma." -Stevens, 1916

Plant Food Storage

"Diagram to show food from the leaves descending through the sieve tubes and being stored in the medullary…

"Diagram to show the relation of the food-conducting tissues of the leaf to those of the stem; and in the stem the relation of these tissues of one year to those of preceding years. The dotted line between phloem and xylem stands for the cambium. The figures at the bottom of the diagram indicate the age in years of the zones of tissues in phloem and xylem." -Stevens, 1916

Food Tissues

"Diagram to show the relation of the food-conducting tissues of the leaf to those of the stem; and in…

"Diagram showing the transport of food through the sieve tubes, medullary rays and tracheal tubes, and its storage in the parenchyma cells of the wood and bark. The black bodies in the cells indicate stored food." -Stevens, 1916

Sieve Tube Food Transportation

"Diagram showing the transport of food through the sieve tubes, medullary rays and tracheal tubes, and…

"Formation of an interior, globular, lysigenous gland of the leaf of Dictamnus fraxinella. A, g, g and c, mother cells of the gland; c, from the protoderm, and g, g, from the fundamental tissue. B, older stage where the cells have begun to form the secretion." -Stevens, 1916

D. Fraxinella Gland Formation

"Formation of an interior, globular, lysigenous gland of the leaf of Dictamnus fraxinella. A, g, g and…

"Lysigenous gland in the leaf of Dictamnus fraxinella. B, young gland, with cells beginning to secrete oil; C, mature gland where the secreting cells have broken down and left their secretion within the cavity thus formed; o, large drop of secreted oil." -Stevens, 1916

Leaf Gland

"Lysigenous gland in the leaf of Dictamnus fraxinella. B, young gland, with cells beginning to secrete…

"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…

"Glands from the leaf of Ribes nigrum. A, young stage in the development of the gland where the cuticle is already being pushed up by the secretion, i. B, complete gland; k, secreting cells; h, cavity between the secreting cells and cuticle occupied by the secretion." -Stevens, 1916

Leaf Glands

"Glands from the leaf of Ribes nigrum. A, young stage in the development of the gland where the cuticle…

"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…

"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…

"Glandular hair from the petiole of Pelargonium zonale. e, secretion from the globular gland on which it rests." -Stevens, 1916

Hair, P. Zonale

"Glandular hair from the petiole of Pelargonium zonale. e, secretion from the globular gland on which…

"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."…

"Hydatode from the leaf of Phaseolus multiflorus." -Stevens, 1916

P. Multiflorus Hydatode

"Hydatode from the leaf of Phaseolus multiflorus." -Stevens, 1916

"Radial longitudinal section through a hydatode from the leaf margin of Primula sinensis. i, upper, and j, lower epidermis; h, palisade cell; e, thin-walled parenchyma, called epithem; g, intercellular space; f, guard cell of a water stoma; k, tracheal elements." -Stevens, 1916

P. Sinensus Hydatode

"Radial longitudinal section through a hydatode from the leaf margin of Primula sinensis. i, upper,…

"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…

"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,…

"B, cells from the petal of Lupinus luteus with yellow chromoplasts." -Stevens, 1916

L. Luteus Cell

"B, cells from the petal of Lupinus luteus with yellow chromoplasts." -Stevens, 1916

"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 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 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 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…

"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,…

"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…

"Showing the effect of cutting across the veins on the removal of food from the leaf. A, all of the main veins are cut across near their bases; B, the mid-vein alone has been severed. The stippled areas indicated the starch reaction with the iodine test." -Stevens, 1916

Cut Leaf Veins

"Showing the effect of cutting across the veins on the removal of food from the leaf. A, all of the…

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,…

"Water-storage tracheids in the leaf of Euphorbia splendens. b, b, water-storage tracheids; d, mesophyll cells; c, branch from a milk tube." -Stevens, 1916

E. Splendens Leaf

"Water-storage tracheids in the leaf of Euphorbia splendens. b, b, water-storage tracheids; d, mesophyll…

"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…

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…

"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;…

"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…

"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…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. A, beginning of ovule at o." -Stevens, 1916

Megaspore Formation Stage 1

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. J, continued nuclear division has resulted in eight, namely, three antipodal nuclei, an, at the upper end of the megaspore cavity, two polar nuclei, l, in process of fusion, egg cell, eg, two synergids, s, s." -Stevens, 1916

Megaspore Formation Stage 10

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. K, showing only the lower half of the megaspore or embryo-sac cavity, with pollen tube, pt, and male nucleus, mn, fusing with egg cell, eg, and second male nucleus, mn2, uniting with primary endosperm nucleus, pe; s, synergid." -Stevens, 1916

Megaspore Formation Stage 11

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. L, later stage in the embryo-sac, an, antipodal cells, em, beginning of the embryo by division of fertilized egg cell; five dividing nuclei descended from primary endosperm nucleus." -Stevens, 1916

Megaspore Formation Stage 12

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. B, nu, nucellus" -Stevens, 1916

Megaspore Formation Stage 2

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. Ca, nu, nucellus, a, archesporium; in, forward growth of tissue to form the integument; Cb, nu, nucellus; in, integument." -Stevens, 1916

Megaspore Formation Stage 3

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. D, more highly magnified drawing of o in A showing archesporial cell at a." -Stevens, 1916

Megaspore Formation Stage 4

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. E, a, archesporial cell enlarged and ready for division; nu, tissue of the nucellus." -Stevens, 1916

Megaspore Formation Stage 5

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. F, a, archesporial cell dividing, nu, nucellus." -Stevens, 1916

Megaspore Formation Stage 6

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. G, row of four megaspores descended from the archesporial cell, only the upper one, m, functional, the other soon disintegrate." -Stevens, 1916

Megaspore Formation Stage 7

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. H, megaspore, m, enlarging, the others disappearing." -Stevens, 1916

Megaspore Formation Stage 8

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells. I, nucleus of the megaspore, divided into two, md." -Stevens, 1916

Megaspore Formation Stage 9

"Stages in the formation of the megaspore, its germination, fertilization of the egg and endosperm cells.…

The anther and archesporium in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Anther

The anther and archesporium in the stages of "formation of anthers and pollen grains or microspores…

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…

The archesporium in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Archesporium

The archesporium in the stages of "formation of anthers and pollen grains or microspores of Silphium."…