The Microorganisms gallery offers 172 images of microbiology and several types of microorganisms. Microorganisms, also known as microbes, are organisms that are microscopic, and are usually too small to be seen by the naked human eye.

"Life history of Gregarina. 1. Young forms (a, b, c) emerging from intestinal cells (i.c.); i.n., nucleus of intestinal cell. 2. Two forms conjugating (G. blattarum). 3. Spore formation within a cyst. 4. Adult with deciduous head-cap (c.c.), and a cuticular partition dividing the cell into an anterior part (A) and a posterior part (B); n., the nucleus. 5. A spore within its spore-case (sp.c.)." -Thomson, 1916

Gregarina

"Life history of Gregarina. 1. Young forms (a, b, c) emerging from intestinal cells (i.c.); i.n., nucleus…

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of…

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina

"Gregarina, contents divided into pseudo-navicellae. GREGARINIDAE. A family or other major group of…

"Gregarina, free pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina

"Gregarina, free pseudo-navicellae. GREGARINIDAE. A family or other major group of endoplastic protozoans,…

"Gregarina of Earthworm, encysted. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina Encysted

"Gregarina of Earthworm, encysted. GREGARINIDAE. A family or other major group of endoplastic protozoans,…

"Gregarina of Earthworm. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Gregarina of Earthworm

"Gregarina of Earthworm. GREGARINIDAE. A family or other major group of endoplastic protozoans, having…

"Gregarina, their free amoebiform contents. GREGARINIDAE. A family or other major group of endoplastic protozoans, having spheroidal, ovoid, or elongated bodies, sometimes with a segmental constriction, and occasionally one end of the body beaked with an epimerite bearing curved horny spines." -Whitney, 1911

Amoebiform Gregarina

"Gregarina, their free amoebiform contents. GREGARINIDAE. A family or other major group of endoplastic…

"End-to-end union of gregarines." -Thomson, 1916

Gregarines

"End-to-end union of gregarines." -Thomson, 1916

Grovia Oviformis is a type of Foraminifera (a class of unicellular animal/protozoa). They are almost always marine in distribution and typically have limy shells.

Grovia Oviformis

Grovia Oviformis is a type of Foraminifera (a class of unicellular animal/protozoa). They are almost…

"Showing the Effect of Variations in Temperature on Bacteria Growth. a, a single bacterium; b, its progeny in twenty-four hours at fifty degrees; c, its progeny in twenty-four hours at seventy degrees." — Blaisedell, 1904

Bacteria growth

"Showing the Effect of Variations in Temperature on Bacteria Growth. a, a single bacterium; b, its progeny…

The body is enclosed in a glassy shell composed of flint. The shell is perforated by numerous holes through which the pseudopodia are emitted, and it is usually of extreme beauty, being sculptured in various ways, and often adorned with spines.

Haliomma Hexacanthum

The body is enclosed in a glassy shell composed of flint. The shell is perforated by numerous holes…

Haliphysena Tumanvitzii; living specimen showing the wineglass-shaped shell built up of sand-grains and sponge-spicules, and the abundant protoplasm p, issuing from the mouth of the shell and spreading partly over its projecting constituents.

Haliphysena Tumanvitzii

Haliphysena Tumanvitzii; living specimen showing the wineglass-shaped shell built up of sand-grains…

"Hypothalline condition of Lecanora cinera, showing the origin of the first Cortical Gonidiogenous Cellules." —The Encyclopedia Britannica, 1910

Hypothalline

"Hypothalline condition of Lecanora cinera, showing the origin of the first Cortical Gonidiogenous Cellules."…

An illustration of a young imperforata with shell dissolved and protoplasm so as to show the seven nuclei.

Young Imperforata

An illustration of a young imperforata with shell dissolved and protoplasm so as to show the seven nuclei.

"A colonial flagellate Infusorian--Proterospongia haeckelii. There are about 40 flagellate individuals. a, nucleus; b, contractile vacuole; c, amoeboid unit in gelatinous matrix; d, division of an amoeboid unit; e, flagellate units with collars contracted; f, hyaline outer membranes; g, unit forming spores." -Thomson, 1916

Infusorian

"A colonial flagellate Infusorian--Proterospongia haeckelii. There are about 40 flagellate individuals.…

Related to the Paramecians. These are remarkable for their size and voracity; they sometimes attain the length of a twelfth of an inch.

Kondylostoma Patens

Related to the Paramecians. These are remarkable for their size and voracity; they sometimes attain…

"Liteocircus annularis. cent. caps, central capsule; ext. caps. pr, extra-capsular protoplasm; int. cap. pr, intra-capsular protoplasm; nu, nucleus; psd, pseudopods; skel, skeleton; z, cells of zooxanthella." -Parker, 1900

L. Annularis

"Liteocircus annularis. cent. caps, central capsule; ext. caps. pr, extra-capsular protoplasm; int.…

Diagram of a lancelet. The mouth is surrounded by a circle of tentacles; below the notochord is a row of gill slits; the vent is near the posterior (right) end below.

Lancelet

Diagram of a lancelet. The mouth is surrounded by a circle of tentacles; below the notochord is a row…

The prehistoric vertebrate, the lancelet or Amphioxus.

Lancelet

The prehistoric vertebrate, the lancelet or Amphioxus.

"Lateral view of Amphioxus. The notochord runs from tip to tip. t., Tentacular cirri; G., reproductive organs; a.p., atriopore; a., position of anus; 40 and 62, indicate number of myotomes." -Thomson, 1916

Lancelet

"Lateral view of Amphioxus. The notochord runs from tip to tip. t., Tentacular cirri; G., reproductive…

"Diagram of the anatomy of Amphioxus, drawn as a semi-transparent object. a, anus; a.p., atrial pore; c.f., caudal fin; cir., cirri, on the edge of the vestibule leading to the mouth; d.f., dorsal fin; r, fin rays; g, gill or branchial structures consisting of alternate slits, through which the water passes, and supporting pates, in the walls of which are the blood vessels; in., intestine, from which as a diverticulum springs l., the liver; m, the mouth surrounded by a ringed velum; my., myotomes or muscle segments; n.c., notochord; o., ovaries; s.c., spinal cord; v.f., ventral fin." -Galloway, 1915

Lancelet

"Diagram of the anatomy of Amphioxus, drawn as a semi-transparent object. a, anus; a.p., atrial pore;…

"Amphioxus lanceolatus. A, ventral; B, side view of the entire animal. an, anus; atrp, atriopore; cd. f, caudal fin; cir, cirri; dors. f, dorsal fin; dors. f. r. dorsal fin-rays; gon, gonads; mtpl, metapleure; myom, myomeres; nch, notochord; or. hd, oral hood; vent. f, ventral fin; vent. f. r, ventral fin-rays." -Parker, 1900

Lancelet

"Amphioxus lanceolatus. A, ventral; B, side view of the entire animal. an, anus; atrp, atriopore; cd.…

Lancelet fish (Branchiostoma) is sometimes called amphioxus, the type of the class Leptocardii, is a little creature, half and inch to four inches long. A lancelet may be regarded as a vertebrate reduced to its lowest terms. Instead of a jointed backbone, it has a cartilaginous notochord, running from the head to the tail. A nervous cord lies above it, enclosed in a membranous sheath. No skull is present and the nerve cord does not swell into a brain There are no eyes and no scles. The mouth is a vertical slit, without jaws. In this diagram we see the California lancelet twice the natural size, showing (g) gills, (l) liver, (m) mouth, (n) nerve cord, (nc) notochord.

Lancelet

Lancelet fish (Branchiostoma) is sometimes called amphioxus, the type of the class Leptocardii, is a…

"Amphioxus lanceolatus. A, transverse section of the pharyngeal region. a, dorsal aorta; b, atrium; c, notochord; co, coelom; e, endostyle; g, gonad; kb, branchial lamellae; kd, pharynx; l, liver; my, myomere; n, nephridium; r, neuron or dorsal nerve tube; sn, spinal nerves; sp, gill-slits. B, transverse section of the intestinal region; atr, atrium; coel, coelom; d. ao, dorsal aorta; int, intestine; myom, myomere; nch, notochord; neu, neuron; s. int. v, subintestinal vein." -Parker, 1900

Lancelet Section

"Amphioxus lanceolatus. A, transverse section of the pharyngeal region. a, dorsal aorta; b, atrium;…

"Early stages in the development of Amphioxus. 1. Ovum with germinal vesicle; 2. four-cell stage; 3. external appearance of blastula; 4. blastula in section; 5. beginning of gastrula stage; 6. section of completed gastrula." -Thomson, 1916

Lancelet Stages

"Early stages in the development of Amphioxus. 1. Ovum with germinal vesicle; 2. four-cell stage; 3.…

"Section of <em>Ampioxus</em>, fr, fin ray; ct, connective tissue; nc, notochord, ; snc, supraneural crest"&mdash;Finley, 1917

Section of a lancelet

"Section of Ampioxus, fr, fin ray; ct, connective tissue; nc, notochord, ; snc, supraneural…

"Side view of <em>Amphioxus</em>: fs, fin supports; nc, notochord; ot, oral tentacles."&mdash;Finley, 1917

Side view of lancelet

"Side view of Amphioxus: fs, fin supports; nc, notochord; ot, oral tentacles."—Finley,…

"Characteristic groups of Micrococci. Micrococcus prodigiosus." &mdash; The Encyclopedia Britannica, 1910

Micrococci

"Characteristic groups of Micrococci. Micrococcus prodigiosus." — The Encyclopedia Britannica,…

"Characteristic groups of Micrococci. Micrococcus vaccinae." &mdash; The Encyclopedia Britannica, 1910

Micrococci

"Characteristic groups of Micrococci. Micrococcus vaccinae." — The Encyclopedia Britannica, 1910

"Characteristic groups of Micrococci. Zoogloea stage of a Micrococcus, forming a close membrane on infusion." &mdash; The Encyclopedia Britannica, 1910

Micrococci

"Characteristic groups of Micrococci. Zoogloea stage of a Micrococcus, forming a close membrane on infusion."…

Types of microorganisms. Labels: a, micrococci arranged singly; in twos, diplococci- if all the micrococci at a were grouped together, they would be called staphylococci- and in fours, sarcinae; b, micrococci, in chains streptococci; c and d, bacilli of various kinds, one is represented with flagellum; e, various forms of spirilla; f, spores, either free or in bacilli.

Types of Microorganisms

Types of microorganisms. Labels: a, micrococci arranged singly; in twos, diplococci- if all the micrococci…

"Microspira Comma, Schroeter." &mdash; The Encyclopedia Britannica, 1910

Microspira Comma

"Microspira Comma, Schroeter." — The Encyclopedia Britannica, 1910

"Indirect or mitotic division; A, resting mother nucleus; B, coil stage, with the centrosomes separating; C, D (metaphase), and H, stages in the division of the chromosomes; F, diastroid (anaphase) stage; G and H show the return of the daughter nuclei to the coil and to the resting condition, and division of the cytoplasm, and the formation of the dividing wall: c, centrospheres; cl, chromatin coil; chr, chromosomes; nu., nucleus; n, nucleoius; sp, nuclear spindle; w, cell wall." &mdash; Galloway

Mitotic Division

"Indirect or mitotic division; A, resting mother nucleus; B, coil stage, with the centrosomes separating;…

"The Monads are infusorial animalcules which make an early appearance in vegetable infusions. They have no skin; the substance of their bodies can shorten itself or draw itself out more or less; their organization is extremely simple."

Monas Lens

"The Monads are infusorial animalcules which make an early appearance in vegetable infusions. They have…

"Life history of Monocystis. 1. Young Gregarine lying within a sperm mother cell of earthworm. 2. Association of two Gregarines within a cyst, ready to form gametes. 3. Numerous spore-cases (sp.c., pseudonavicellae) within a cyst. 4. A spore-case with eight spores (sp.) and a residual core (rb)." -Thomson, 1916

Monocystis

"Life history of Monocystis. 1. Young Gregarine lying within a sperm mother cell of earthworm. 2. Association…

"Colonies of Myconostoc enveoped in diffluent matrix." &mdash; The Encyclopedia Britannica, 1910

Myconostoc

"Colonies of Myconostoc enveoped in diffluent matrix." — The Encyclopedia Britannica, 1910

"Colonies of Myconostoc enveoped in diffluent matrix." &mdash; The Encyclopedia Britannica, 1910

Myconostoc

"Colonies of Myconostoc enveoped in diffluent matrix." — The Encyclopedia Britannica, 1910

"Colonies of Myconostoc enveoped in diffluent matrix." &mdash; The Encyclopedia Britannica, 1910

Myconostoc

"Colonies of Myconostoc enveoped in diffluent matrix." — The Encyclopedia Britannica, 1910

"Flagellum of Noctiluca miliaris (highly magnified). s, transversely striated substance; b, base of attachment to body of animal." &mdash; Encyclopedia Britannica, 1893

Noctiluca Miliaris

"Flagellum of Noctiluca miliaris (highly magnified). s, transversely striated substance; b, base of…

"A compound foraminiferan, Nodosaria. a, aperture of shell; f, food particles captured by the strands of protoplasm outside the shell; n, nucleus; sh, shell, 1-4, the successive chambers of the shell; 1, being the oldest." &mdash; Galloway

Nodosaria

"A compound foraminiferan, Nodosaria. a, aperture of shell; f, food particles captured by the strands…

One group will take the spherical form and produce a shell in the shape of the nautilus. In this case, the external convolutions conceal those previously formed.

Nummulina Perforta

One group will take the spherical form and produce a shell in the shape of the nautilus. In this case,…

<i>Grovia oviformis</i> is a type of Foraminifera (a class of unicellular animal/protozoa). They are almost always marine in distribution and typically have limy shells.

Nummulites Cummingii

Grovia oviformis is a type of Foraminifera (a class of unicellular animal/protozoa). They are almost…

One group will take the spherical form and produce a shell in the shape of the nautilus. In this case, all the convolutions are visible.

Operculina

One group will take the spherical form and produce a shell in the shape of the nautilus. In this case,…

A collage of different types of organic life including deer in a forest, farmers harvesting wheat, and an alligator in a tropical region.

Organic Life, Collage of

A collage of different types of organic life including deer in a forest, farmers harvesting wheat, and…

"Paramecium in optical section. A, anterior end; c, tilia; e.d., ectosarc; e.n., endosarc; f.v., food "vacuole"; g, gullet; N, meganucleus; n, micronucleus; o, oral groove, leading to the mouth; p.v., pulsating vacuoles in different stages of contraction; tr., trichocysts; v, food vacuole in process of formation." &mdash; Galloway

Paramecium

"Paramecium in optical section. A, anterior end; c, tilia; e.d., ectosarc; e.n., endosarc; f.v., food…

"Paramoecium. ad. Adult form, showing cilia, "mouth," contractile vacuoles, etc. div. Transverse division. con. Conjugation." -Thomson, 1916

Paramecium

"Paramoecium. ad. Adult form, showing cilia, "mouth," contractile vacuoles, etc. div. Transverse division.…

In this image, (a) represents the parasites in the various stages of development, and (b), the larger animalcule on which they have established themselves.

Paramecium Aurelia and its Parasites

In this image, (a) represents the parasites in the various stages of development, and (b), the larger…

"Paramecium Bursaria is the only species of Paramecium that forms symbiotic relationships with algae, and are often used in biology classrooms as examples of protozoans, and as examples of symbiosis."

Paramecium Bursaria (Pritchard)

"Paramecium Bursaria is the only species of Paramecium that forms symbiotic relationships with algae,…

"Paramecium. I, transverse fission; 2-5, stages in conjugation. The meganucleus gradually disintegrates during the process and the micronucleus by two successive divisions forms four micronuclei. Two of these disintegrate. One of the remaining micronuclei (n3) in each animal passes into the other Paramecium and unites with the stationary micronucleus (n4), thus fertilizing it. Later a new meganucleus is formed in each animal by the division of this body. Nucleus n3 is often smaller than n4 and may represent the male element." -Galloway, 1915

Paramecium Division

"Paramecium. I, transverse fission; 2-5, stages in conjugation. The meganucleus gradually disintegrates…

"Paramoecium caudatum. A, the living animal from the ventral aspect; B, the same in optical section: the arrow shows the course taken by food-particles; C, a specimen which has discharged its trichocysts; D, diagram of binary fission; buc. gr, buccal groove; cort, cortex; cu, cuticle; c. vac, vontractile vacuole; f. vac food vacuole; gul, gullet; med, medulla; nu, meganucleus; pa. nu, micronucleus; trch, trichocysts." -Parker, 1900

Paramoecium Caudatum

"Paramoecium caudatum. A, the living animal from the ventral aspect; B, the same in optical section:…

"Planococcus citreus (Menge), Migula." &mdash; The Encyclopedia Britannica, 1910

Planococcus Citreus

"Planococcus citreus (Menge), Migula." — The Encyclopedia Britannica, 1910

"Their shells are usually of a leathery texture, nearly transparent, and usually spring from a root-stalk of similar consistence, which creeps along upon the surface of stones or aquatic plants, in which situations these animals are not uncommon." &mdash; Goodrich, 1859

Plumatella

"Their shells are usually of a leathery texture, nearly transparent, and usually spring from a root-stalk…

Grovia Oviformis is a type of Foraminifera (a class of unicellular animal/protozoa). They are almost always marine in distribution and typically have limy shells.

Polystomella Strigillata

Grovia Oviformis is a type of Foraminifera (a class of unicellular animal/protozoa). They are almost…

"The singular phenomenon of spontaneous division may be witnessed by any one having patience to examine the creature long enough under the microscope, isolated from its innumerable companions. This process is represented here, A and B being the adult, C the same in course of separation, D after its completion."

Propagation of an Infusorian by Spontaneous Division

"The singular phenomenon of spontaneous division may be witnessed by any one having patience to examine…

The circulation of protoplasm (p) in a cell of the stamen-hair of Tradescania. In the channels the granules move back and forth to the various parts of the cell. The remainder of the cell is filled with cell-sap (s) which in these cells is colored.

Protoplasm

The circulation of protoplasm (p) in a cell of the stamen-hair of Tradescania. In the channels the granules…

"Their bodies consist either of aa simple elementary cell, with its contents, or of an aggregation of several of these cells; each, however, still appearing to retain its independent existence. They are generally of a very minute size, and only to be observed with the microscope." &mdash; Goodrich, 1859

Protozoans

"Their bodies consist either of aa simple elementary cell, with its contents, or of an aggregation of…

"Pseudomonas Macroselmis, Migula." &mdash; The Encyclopedia Britannica, 1910

Pseudomonas Macroselmis

"Pseudomonas Macroselmis, Migula." — The Encyclopedia Britannica, 1910

"Pseudomonas pyocyanea" &mdash; The Encyclopedia Britannica, 1910

Pseudomonas Pyocyanea

"Pseudomonas pyocyanea" — The Encyclopedia Britannica, 1910

"Pseudomonas Syncyanea, Migula." &mdash; The Encyclopedia Britannica, 1910

Pseudomonas Syncyanea

"Pseudomonas Syncyanea, Migula." — The Encyclopedia Britannica, 1910

"<em>Ptychodera flava</em> (New Caledonia)." &mdash; Encyclopediia Britannica, 1910

Ptychodera flava

"Ptychodera flava (New Caledonia)." — Encyclopediia Britannica, 1910