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Darkfield Illumination Digital Image Gallery

Darkfield illumination transforms specimens into bright, highlighted structures superimposed on a very dark or black background. When the MIC-D digital microscope illuminator is positioned at highly oblique angles (over 25 degrees from the optical axis), semi-transparent specimens can be readily observed and captured with the accompanying interface software. This gallery demonstrates the darkfield imaging ability of the microscope on a wide variety of specimens.

Acanthocephala (Spiny-Headed Worm) - Members of the phylum Acanthocephala are entirely endoparasitic, but when compared to other invertebrate parasites such as the roundworms (phylum Nematoda) and tapeworms (phylum Platyhelminthes, class Cestoda), they are relatively rare. However, acanthocephalans have succeeded by infiltrating niches within every vertebrate class.

American Beachgrass - American beachgrass grows naturally on dunes that border beaches along the Atlantic and Gulf of Mexico coastlines, but does not fare well in the richer, darker, and less oxygenated soils of the inland marshes and the bay sides of barrier islands.

Ants (Formicidae) - One of the most successful insects to inhabit the Earth during the past 100 million years is the ant, a member of the class Insecta. Within the order Hymenoptera that also includes the wasps and bees, the 252 genera and more than 20,000 species of ants belong to a single family, Formicidae.

Aphids - Known also as plant lice or ant cows, aphids create significant economic hardships for farmers, horticulturists, and home gardeners by causing leaf curling and other deformations. These insects are also responsible for sooty molds, wilting, damage to fruits and vegetables, and in some cases, they act as vectors for plant diseases. Although aphids rarely kill their plant hosts, the mouthparts are sometimes contaminated during feeding on diseased plants. When the aphid moves to the next plant host, it acts as a carrier, infecting other plants with its tainted mouthparts.

Aurelia Ephyra-Stage Jellyfish - Members of the jellyfish in the class Scyphozoa undergo a complex life cycle including a larval medusa or ephyra stage. The genus Aurelia demonstrates the typical life stages for this class of invertebrates, which also include the free-swimming planula, the stalked and tentacled schyphistoma polyp, the strobila bud, and the mature medusa stages.

Bacterial Capsules - Similar to plant cells, bacteria are characterized by a protective cell wall surrounding the cytoplasmic membrane. However, some species of bacteria feature a third protective covering, the capsule, which is composed either of proteins, or more commonly of polysaccharides, a class of complex carbohydrates.

Bauxite Ore - As a convenient and common source of alumina, bauxite ore was first commercially mined in Jamaica in 1854. Almost 35 years later, Karl Joseph Bayer described the process (now known as the Bayer Process) that dramatically reduced the cost of aluminum metal production and moved it from the realm of precious metals into that of everyday commodity.

Butterfly Proboscis - A tubular sucking organ, the proboscis enables a butterfly to extract sweet nectar from the flowers it feeds upon, regardless of the shape of the blossom. When not being used, a butterfly's proboscis is rolled up out of the way.

Canine Hookworm - Canine hookworm larvae hatch in soil where they develop and await a passing host that is susceptible to infestation. A dog may ingest soil containing the larvae, or more commonly, the larval hookworms enter the animal by penetrating the paws. Over time, the larvae migrate within the body to the lungs, ascend the respiratory tract, and eventually are swallowed. They move through the digestive system until they reach the lining of the small intestine, where they attach and feed, starting the cycle once again.

Chicken Embryos - The chick or baby chicken is not only a favorite as a reminder of spring and as a live Easter gift for children in the United States, but is also well studied by embryologists, toxicologists, and histologists. Because of their relatively low cost, abundance, and year-round supply, chicken embryos make ideal laboratory organisms.

Cnidaria Fossil - The phylum Coelenterata, also known as Cnidaria, includes the marine corals, sea fans, sea pens, sea anemones, hydras, and jellyfish. Hydras also have freshwater representatives and are the exception in the coelenterate taxon since they do not exhibit a medusa or "jellyfish" life stage. Specialized stinging cells known as nematocysts or cnidae (thus, the alternative phylum name) are used to capture, hold, and reel in prey, as well as to assist in locomotion and defense.

Dandelion Fruit - Not the typical bright colored, juicy, and sweet fruit (such as a ripe plum or peach), the fruit of the dandelion bears more resemblance to a white or grayish parachute. The dandelion fruits are attached to the seeds by long stalks, and are a critical dispersal mechanism for this weedy perennial herb that depends on wind rather than animals, water, gravity, or fruit eruptions for completing its life cycle.

Dead Leaf Butterfly Wing - In the family Nymphalidae, the dead leaf butterflies (Kallima species) from Southeast Asia and East Africa get their common name from the uncanny resemblance of their wing undersides to dead plant leaves. So close is the mimicry, the wing pattern appears to feature "moldy spots of decay", a "midrib" for the "leaves," and the tail touches the twig and appears like a leaf stalk. Less distinct dark lines run obliquely from the center line towards the wings' margins, mimicking the veins of a leaf.

Deer Tick (Ixodes dammini) Larvae - Throughout the woods of North America, the tiny deer tick (Ixodes dammini) is rapidly replacing the mythical "Boogeyman" and the fabled big, bad wolf as a means of imparting caution and obedience to children, in the face of fear. Since the 1980s, nymphal and adult deer ticks have acted as the vector for Lyme disease in North America.

Dogfish Shark Placoid Scales - Dogfish sharks make up one subfamily of the dogfish shark family, and are characterized by a hard spine at the base of each of the two dorsal fins. Other species of the dogfish shark family that are called dogfish include the Atlantic black dogfish and the green dogfish, found in deep waters of the Gulf of Mexico. The green dogfish, along with several other members of the dogfish shark family, is luminescent.

Fern Sori - Fern is a common name for the cryptogamous (spore-producing) plants belonging to the division Filicophyta (also called Filicinophyta). These are primitive vascular plants with true roots, stems, and complex leaves, comprising about 150 genera and as many as 15,000 species.

Foraminifera - Microscopic unicellular organisms, the Foraminifera are a wide-ranging marine taxon found at all depths worldwide. Constructing shells of various materials, following the death of the organisms, concentrations of their shells may achieve densities exceeding tens of thousands of individuals per cubic centimeter of sediment, which often occupy specialized ecological niches.

Frog Striated Muscle - The celebrated jumping frog of Mark Twain's Calaveras County, California would not have been so famous (nor would Mr. Twain) without striated muscles. Striated muscles typical of the rear leg skeletal muscles enable frogs to leap long distances.

Fruit Fly (Drosophila melanogaster) - The cornerstone experimental animal in the study of cellular and molecular genetics for over 50 years has been the ubiquitous fruit fly (Drosophila melanogaster). Whether mutated to a wingless, white-eyed, or barred, phenotype, or wild, it is the fruit fly that each budding geneticist is first exposed to. More recently, Drosophila are playing a starring role in developmental biology with particular emphasis on this dipteran's embryonic stages.

Fucus Male Conceptacle - Fucus, better known as kelp or seaweed, is a genus of exclusively-marine brown macroalgae in the family Phaeophyceae. The phytopigment fucoxanthin masks the natural green of the chlorophylls in these multicellular intertidal and subtidal plants.

Goniatitic Cephalopod Fossil - Cephalopods represent a class of mobile predacious carnivore mollusks that possess a bilaterally symmetrical body, a prominent head, and a modified foot composed of tentacles. The digital image featured below was captured from a relatively low magnification view of a polished thin section from a cephalopod fossil having a goniatitic suture morphology.

Grantia Sponge - Sponges, colonial animals in the phylum Porifera, are primitive invertebrates that are dominated by marine species. Typically, they are benthic, sessile filter feeders that are asymmetrical. Grantia is a genus of calcareous marine sponges that is sometimes referred to as Scypha in older texts. This group of sponges demonstrates the sycon body plan in which the wall of the colony is folded into a series of internal and external canals that circulate water to bring in dissolved oxygen and prey while removing waste products.

Grasshopper Malpighian Tubules - The challenges of survival for terrestrial insects such as the grasshoppers (order Orthoptera) include conserving water, particularly in arid regions of the world including the deserts and grasslands. As excretory organs, the Malpighian tubules not only get rid of nitrogenous wastes, they help properly maintain the internal ionic balance of the insect.

Honeybee Stinger - When former heavyweight champion boxer Muhammad Ali said he wanted to float like a butterfly, but sting like a bee, he probably had the honeybee on his mind. Unlike many other members of the order Hymenoptera, honeybees usually do not sting unless provoked.

House Fly (Musca domestica) - The common house fly, Musca domestica, is considered to be a nuisance as well as a vector for many diseases affecting both humans and animals. From an entomologist's point of view, this dipteran is the compilation of a remarkable suite of adaptations including incredible flying speeds and agility, high-level chemosensory abilities and pressure detectors, and complex compound eyes that rival some of the military's best remote sensing devices.

Human Flea (Pulex irritans) - The human flea (Pulex irritans) is one of more than 1,600 species and subspecies of flea that populate the Earth from the Arctic Circle to the deserts of Africa. Fleas, members of the insect order Siphonaptera, parasitize mammals and birds for their blood, using specialized anatomical structures to attach to the hosts' skin.

Human Head Louse - Demonstrating a near-perfect illustration of coevolution, the six legs of the head louse are adapted for efficiently grasping the person's hair shafts. Head lice infest new hosts mainly by direct head-to-head contact with infected hair, but may be transferred by contaminated combs, hats, or other hair and head accessories. For a brief period of time, human head lice can survive living freelty on upholstered furniture and bedding. Children are more frequently infested than adults and louse infestations seem to have little to do with personal hygiene, sanitation practices, or socioeconomic classes.

Human Tooth Root - As the anchor to a human tooth, the root extends into the bone of the jaw and houses the nerves and blood vessels that carry nutrients to the tooth. A tough, yellowish bone-like tissue, cementum, covers the root and helps hold the tooth in its socket.

Insect Spiracles - Spiracles, specialized structures featured in the class Insecta, provide the breath of life. While the tracheae constitute the respiratory system of the adult insect, spiracles are the external apertures or openings through which gases are exchanged with the environment. Usually paired, spiracles are repeated in each segment of the thorax and abdomen, one on each side.

Jute - Jute is a strong, coarse natural fiber used for making burlap, gunny, floor coverings, and ropes. Two annual plants in the linden family (Tiliaceae) from India, Cochorus capsularis (white) and C. olitorius (tossa) are the sources for jute fiber.

Lamprey Larva (Ammocoetes) - The larval stage of the primitive lamprey, known as an ammocoetes larva, serves to illustrate the much-maligned concept of ontogeny recapitulating phylogeny by resembling the more primitive chordate, Amphioxus, in morphology and behavior. The ammocoetes displays many characteristics of ancient chordates, and shared embryological traits of the vertebrates including gill slits, a notochord, myomeres (body muscle segments), a dorsal nerve cord, a dorsal fin, and a primitive nervous system with a brain and eyes.

Leeches - Leech is a common name for over 650 species of largely freshwater, carnivorous worms that comprise the class Hirudinea in the phylum Annelida. Although commonly known as the bloodsuckers, some species are not parasitic and are free-living in streams and ponds, feeding on aquatic insects and other freshwater invertebrates.

Lycra Spandex - As the premiere synthetic stretch fabric, lycra spandex is the trade name for DuPont's version of the long-chain polymeric fiber. Invented at DuPont by American scientist Joseph C. Shivers in 1959, spandex sprang on the market as a replacement for rubber (latex) in women's foundation garments.

Metridium - A common genus of sea anemone, Metridium is found throughout the world's oceans. Usually white, but also tan, brown, or orange, the plumose anemone (M. senile) is often used as a dissection specimen in comparative anatomy classes and is found in the temperate seas of the Northern Hemisphere including the Atlantic and Pacific Coasts of North America and the coastal waters of Japan.

Mixed Green Algae - Prominent members of the kingdom Protista, algae are most common in aquatic habitats, but occur in nearly every environment. They range in size from unicellular microscopic pond inhabitants to giant kelp that reaches 200 feet (60 meters) in length.

Mold (Aspergillus) Conidiophores - As one of the two common genera of molds on fruits and other foods such as grain, wheat, and bread, species of the genus Aspergillus are distinguished from Penecillium species by the origin of their spore-bearing stalks or conidiophores. In Aspergillus, the conidiophore arises from a foot-cell, a vegetative mycelium.

Monarch Butterfly (Danaus plexippus) Wing - As the common name implies, the monarch butterfly (Danaus plexippus) is the king of the insect order Lepidoptera. Known throughout North America, these colorful butterflies are able to migrate long distances (up to 3,000 miles) in round-trips to winter roosts in Mexico and California. Their migration is monitored by students through Monarch Watch, an international tagging program based at the University of Kansas in Lawrence, and using numbered, 9-millimeter-diameter round, polypropylene tags placed on the underside of hindwings.

Morpho Butterfly Wing - As a genus of beautiful mostly iridescent blue butterflies, the species of Morpho in the family Morphidae are found in the tropical rainforests of Central and South America. The diurnal flashy butterflies are still at night, folding their brilliant blue wings up and over their bodies and revealing their cryptic under sides as they hang from branches and leaves, blending into their backgrounds.

Mosquito Pupa - As with many other insect species, mosquitoes in the genus Culex undergo several life stages between the egg and maturity. Because of their hard, chitinous exoskeletons, insects are forced to molt as they grow. In the dramatic transformation from an aquatic larva to a flying adult, the mosquito undergoes an intermediate pupal stage.

Mucor Zygotes - Molds of the genus Mucor are found in soil and as saprobes of plants and manure in the wild, and as a common contaminant of stored and processed foods in the kitchen. There are about 50 species described worldwide and many plague water-damaged or moist structural materials and can inflict allergies on exposed people.

Parenchyma Abscission Layer - The abscission layer, a barrier of thin-walled parenchyma cells, develops across the stem (or petiole) at the base of a leaf, flower, or fruit as it approaches the time of falling from a plant. Abscission is the process that should be recognized for creating the beautiful autumn colors of deciduous trees in temperate regions, and this specialized layer acts as the breaking point for separating the plant from its terminal appendages.

Pectinatella Bryzoans - Resembling gelatinous detritus or aquatic plant growth on submerged sticks and other substrates, bryozoans are primarily marine, but are also found in freshwater rivers and impoundments. Commonly referred to as the moss animals, these sessile colonial creatures were thought to be plants similar to their ecological analogs, the corals, until the mid-1700s. Of the thousands of species worldwide, one class, Phylactolaemata, is found exclusively in fresh water. Known as the jelly blobs or simply "blobs", Pectinatella magnifica is a relatively common North American freshwater species of the phylum Ectoprocta.

Pennaria Hydrozoa - Belonging to the phylum Coelenterata, class Hydrozoa is best known for the polyp state that usually forms extensive and relatively beautiful colonies when examined with the microscope.

Pig Embryo - As one of the first dissection animals experienced in comparative anatomy laboratory, fetal or embryonic pigs are very well studied because their development and organ systems reasonably parallel human development. Pig embryos are also playing a role in reproductive biology whether used in embryo transfers for advanced livestock breeding and production, or for studying techniques for improving human fertility and birthing success.

Pig Tooth Enamel Formation - As mammalian omnivores, pig teeth are fairly good models for studying the development and aging of human teeth. Dental enamel is formed by the epithelial cells of the enamel organ including the ameloblasts, the cells that produce enamel matrix proteins.

Pinworms (Enterobius vermicularis) - As the most common nematode parasite of humans in North America and Europe, pinworms (Enterobius vermicularis) infect more than 400 million people worldwide. Living in the large intestine, pinworm infestations may be asymptomatic or result in mild irritations of the gastrointestinal tract.

Planaria - Planaria are members of the phylum Platyhelminthes (flatworms) in the class Turbellaria. Unlike some of the related parasites in the classes Cestoda (tapeworms) and Trematoda (flukes), planarians are largely free-living, freshwater invertebrates found in or near the sediments of ponds and streams. With triangular heads, flat worm-like bodies, and paired eyespots (ocelli) that give the appearance of being cross-eyed, the bilaterally symmetrical turbellarians are relatively easy to recognize. A piece of liver tied to a string makes a great attractant for planaria when tossed into a pond or slow-moving river.

Pleistocene Mammal Bone From Florida - During the Pleistocene in the Cenozoic Era, ranging from 1.8 million years ago to as recently as 11,000 years ago, extant and extinct mammals coexisted with prehistoric humans. As with any other fossilized bones, the Pleistocene mammal bones underwent petrification or mineralization.

Radiolarians - Radiolarians are single-celled protistan marine organisms that distinguish themselves with their unique and intricately detailed glass-like exoskeletons. During their life cycle, radiolarians absorb silicon compounds from their aquatic environment and secrete well-defined geometric networks that comprise a skeleton commonly known as a test.

Sheep Ked Fly - The sheep ked, Melophagus ovinus, a wingless, bloodsucking fly is often misnamed the "sheep tick" because it resembles a large tick. However, as with the other members of the class Insecta, the sheep ked features only six legs and not the requisite eight of the ticks and fellow arachnids.

Shepherd's Purse (Capsella) Embryos - An annual herb of the mustard family (Cruciferae or Brassicaceae), the shepherd's purse (Capsella bursa-pastoris) is a native to the Mediterranean nations. This hardy botanical has accompanied Europeans in their migrations, and it is now found in most every part of the world.

Sodium Chloride (Table Salt) Grains - Salt has been used by mankind before recorded history as a mineral of paramount importance in regulating health, as well as in seasoning food. Sodium chloride, or common table salt, is the most familiar of the salt compounds. Also known as halite, or rock salt, this mineral forms when water evaporates from saline basins.

Spiders - Representatives of the class Arachnida, spiders are found worldwide with about 35,000 known species (4,000 in North America), but less than one percent are dangerous to humans. Even with such impressive numbers, it is estimated that only 20 percent of the spiders of Australia are scientifically catalogued and some arachnologists estimate there may be as many as 170,000 undescribed species worldwide. As insectivores, spiders are valuable to farmers, feeding regularly on agricultural pests.

Tapeworm Scolex - Tapeworms (class Cestoda) are a group of parasitic flatworms (phylum Platyhelminthes) that usually require two hosts, including an invertebrate as an intermediate. The more than 5,000 known species of cestodes are endoparasites, several of which are known to feed on humans.

Termites - In the insect order Isoptera, termites rule the roost. The scientific name refers to the two pairs of equal length wings featured by reproductive adults. Although socially advanced like ants, termites are closely related to the more primitive cockroaches. There are at least 2,750 recognized species placed in 285 genera worldwide, with most tropical or subtropical in distribution.

Trematode Flukes (Echinostoma revolutum) - The digenetic trematode Echinostoma revolutum is an endoparasitic helminth having a wide variety of hosts including ducks, geese, pigeons, chickens, and humans. With part of its life history spent in water bodies, these members of the phylum Platyhelminthes (flatworms) use freshwater snails as their primary hosts and frogs or snails as their secondary intermediate hosts.

Trichuris Whipworms - Whipworms, members of the rather large genus Trichuris, are intestinal parasites having about 60 species that infect mammalian hosts. Two common species, the human whipworm (T. trichiura) and canine whipworm (T. vulpis) display a relatively high degree of host specificity, with canine whipworms only rarely occurring in humans.

Varroa Mite (Varroa jacobsoni) - Known as the varroa mite, Varroa jacobsoni is an ectoparasitic member of the class Arachnida found on honeybees (genus Apis). Originally described from Java in 1904, the mite was located in Hong Kong and the Philippines by 1963 and imported to the United States on infected queen bees by 1979. Now the parasitic mite has spread to most of North America except for isolated locations in Canada.

Volvox - In the division Chlorophyta (green protists), Volvox is a colonial form made up of 500 to 60,000 biflagellated cells embedded in a gelatinous wall. The largest colonies exceed one millimeter in diameter and are easily visible to the naked eye.

Zea (Corn) Kernel - Corn is the common name for the cereal grass widely grown as food for humans and animals. Along with wheat and rice, it is one of the world's chief grain crops and the largest crop grown in the United States. Native to the Americas, corn (Zea mays) is the domesticated variety of the Zea grass family, and originally was cultivated by Native Americans 8,000 to 10,000 years ago.

Contributing Authors

Cynthia D. Kelly, Thomas J. Fellers and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.


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