ClipArt ETC
"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…

"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…

"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."…

"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…

"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,…

"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…

"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,…

"Laticiferous vessels from the cortex of root of Scorozonora hispanica...B, smaller portion." -Stevens, 1916

Root Vessels

"Laticiferous vessels from the cortex of root of Scorozonora hispanica...B, smaller portion." -Stevens,…

"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…

"Different forms of crystals of calcium oxalate. A, from the petiole of Begonia manicata." -Stevens, 1916

Calcium Oxalate Crystals

"Different forms of crystals of calcium oxalate. A, from the petiole of Begonia manicata." -Stevens,…

"Cystoliths from the leaf of Ficus carica. A, complete cystolith; B, cystolith from which the calcium carbonate has been removed for use in other parts of the plant. B is from a leaf that had fallen off in autumn." -Stevens, 1916

Cystoliths

"Cystoliths from the leaf of Ficus carica. A, complete cystolith; B, cystolith from which the calcium…

"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…

"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,…

"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…

"Showing method of association of paternal and maternal chromosomes, at A in all vegetative nuclei, and B, C, D, their manner of separation in all vegetative nuclear divisions. Showing also manner of association of paternal and maternal chromosomes at E in early prophase of spore grandmother cells and the manner of their separation during the division of the grandmother-cell nucleus at F and G. Showing also the longitudinal division of the chromosomes in the spore mother cells in H, and their separation to form the spore nuclei in I, two of the four spores being purely paternal and two purely maternal." -Stevens, 1916

Plant Reproduction

"Showing method of association of paternal and maternal chromosomes, at A in all vegetative nuclei,…

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."…

The primary sporogenous cell (ps) and the primary parietal layer (ppr) in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Cells

The primary sporogenous cell (ps) and the primary parietal layer (ppr) in the stages of "formation of…

The inner layer (i), outer layer (o), sporogenous cells (s) in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Layers

The inner layer (i), outer layer (o), sporogenous cells (s) in the stages of "formation of anthers and…

The sporogenous cells (s), tapetum (t), two parietal layers (oo) in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Cells

The sporogenous cells (s), tapetum (t), two parietal layers (oo) in the stages of "formation of anthers…

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 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 pollen grains beginning to germinate in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Pollen Grains

The pollen grains beginning to germinate in the stages of "formation of anthers and pollen grains or…

The sporogenous cells (s), tapetum (t), two parietal layers (oo) in the stages of "formation of anthers and pollen grains or microspores of Silphium." -Stevens, 1916

Microspore Cells

The sporogenous cells (s), tapetum (t), two parietal layers (oo) in the stages of "formation of anthers…

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…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 1, resting stage of a grandmother cell." -Stevens, 1916

Division of Grandmother Cell Stage 1

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 2, nuclear thread becoming arranged into parallel threads." -Stevens, 1916

Division of Grandmother Cell Stage 2

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 3, synaptic stage." -Stevens, 1916

Division of Grandmother Cell Stage 3

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 4, parallel threads uniting." -Stevens, 1916

Division of Grandmother Cell Stage 4

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 5, double threads so united as to appear as one." -Stevens, 1916

Division of Grandmother Cell Stage 5

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 7, thread transversely segmented into double chromosomes." -Stevens, 1916

Division of Grandmother Cell Stage 7

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 8, diakinesis, that is, chromosomes dispersed about the nuclear membrane." -Stevens, 1916

Division of Grandmother Cell Stage 8

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 9, multipolar spindle stage." -Stevens, 1916

Division of Grandmother Cell Stage 9

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 10, bipolar spindle with double chromosomes aligned at the equator." -Stevens, 1916

Division of Grandmother Cell Stage 10

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 11, reduction division, the double chromosomes separating and at the same time showing longitudinal division, with the longitudinal halves widely apart at their equatorial ends." -Stevens, 1916

Division of Grandmother Cell Stage 11

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 12, formation of daughter nuclei, which are really the nuclei of the mother cells of the spores." -Stevens, 1916

Division of Grandmother Cell Stage 12

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 13, division of mother-cell nuclei, the longitudinally split chromosomes seen in 11 again appearing." -Stevens, 1916

Division of Grandmother Cell Stage 13

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 14, split chromosomes of 13 aligned at the equator ready for the longitudinal halves of each to be drawn apart to opposite poles." -Stevens, 1916

Division of Grandmother Cell Stage 14

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 15, separation of the longitudinal halves." -Stevens, 1916

Division of Grandmother Cell Stage 15

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic. 16, formation of granddaughter nuclei, or nuclei of the spores." -Stevens, 1916

Division of Grandmother Cell Stage 16

"Stages in the division of a grandmother cell of microspores or pollen grains of a lily, somewhat diagrammatic.…

"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. 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.…

"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.…

"Showing the planes in which sections are cut transversely." -Stevens, 1916

Cutting Sections Transversely

"Showing the planes in which sections are cut transversely." -Stevens, 1916

"Showing the planes in which sections are cut longitudinal radially" -Stevens, 1916

Cutting Radially

"Showing the planes in which sections are cut longitudinal radially" -Stevens, 1916

"Showing the planes in which sections are cut longitudinal tangentially." -Stevens, 1916

Cutting Tangentially

"Showing the planes in which sections are cut longitudinal tangentially." -Stevens, 1916

"Showing how to trim a block for cutting longitudinal sections." -Stevens, 1916

Trimming

"Showing how to trim a block for cutting longitudinal sections." -Stevens, 1916

"Simple microtome for clamping to table. P, P, plate glass ways for the section knife; S, milled-head for clamping the object; M, micrometer milled-head for turning the screw that raises the object as the sections are cur; C, milled-head for clamping the microtome to the table." -Stevens, 1916

Microtome

"Simple microtome for clamping to table. P, P, plate glass ways for the section knife; S, milled-head…