Photo Researchers ftp March 2011

Light micrograph of dryopteris, a fern. Section of gametophyte with archegonium. Shows egg, neck, and neck canal cells. Ferns occur worldwide in moist...

Light micrograph of Dryopteris, a fern. Prothallus with young sporophyte developing from fertilized egg (zygote), showing first leaf and first root. F...

BLM botanist Ann DeBolt with slickspot peppergrass (lepidium papilliferum), Canyon County ID.

Bureau of Land Management botanist Ann Debolt with slickspot peppergrass (lepidium papilliferum), Canyon County, ID.

Marsh Wren (Cistothorus palustris) singing. Litchfield, CT.

Vet checking for stress bars on an 18 week old greenwing macaw baby (Ara chloropterus).

A Veterinarian at London's Super Pet hand-feeds an 18 week old Greenwing Macaw (Ara chloroptera).

Vet administering medication to a cinnamon pied white-faced cockatiel (Nymphicus hollandicus).

Mammatus Clouds. Photo near Wakarusa, Shawnee County, Kansas.

Muskrat skull with lower jaw. Note infraorbital foramen high on rostrum.

Skull of a Nutria (Myocastor coypus). The large round infraorbital foramen is a passage for the deep masseter muscle.

A Rocky Mountain Elk (Cervus canadensis nelsoni) wearing a radio collar, part of a reintroduction effort organized by hunters and conservationists in...

Seaside Sparrow (Ammodramus maratimus). Guilford, CT.

Green-tailed Towhee (Pipilo crissalis) perched on branches. Mono Lake, CA.

Beaver (Castor canadensis) skull. Lawrence, Kansas.

Biologists examine micro-organisms to determine health of ecosystem during biological inventory of forest in North Carolina.

A green oasis of plants and micro-organisms in an isolated rocky depression atop Enchanted Rock, a granite dome in central Texas, in April.

A scientist measures a Diamondback Terrapin (Malaclemys terrapin) hatchling. Afterwards the animal will be placed in a marsh. Cape Cod, Massachusetts.

A scientist measures a Diamondback Terrapin (Malaclemys terrapin) hatchling. Afterwards the animal will be placed in a marsh. Cape Cod, Massachusetts.

Polar bear (Ursus maritimus) being relocated by helicopter from the polar bear "jail," Churchill, Manitoba, Canada. Bears are placed in the jail if th...

Jack Russell Terrier with Elizabethan collar after surgery, to keep the dog from licking its wound.

Coast guard workers release a rehabilitated sea turtle (superfamily Chelonioidea); Florida Keys.

Volunteers relocate sea turtle (superfamily Chelonioidea) eggs to a safer site; Miami Beach, Florida.

Scientists gather data on sea turtle (superfamily Chelonioidea) eggs as they prepare to relocate them to a safer site; Miami Beach, Florida.

RHIC collider. View of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, Long Island, New York. RHIC consists of two rings...

Avalanche beginning to form; Switzerland.

Avalanche beginning to form; Switzerland.

Experiment showing the effect of psilocybin on a garden spider. A young female Garden Spider (Araneus diadematus) built a "control web" (A) on one day...

Experiment showing the effect of psilocybin on a garden spider. A young female Garden Spider (Araneus diadematus) built a "control web" (A) on one day...

Experiment showing the effect of psilocybin on a garden spider. A young female Garden Spider (Araneus diadematus) built a "control web" (A) on one day...

Experiment showing the effect of psilocybin on a garden spider. A young female Garden Spider (Araneus diadematus) built a "control web" (A) on one day...

Tormentil (Potentilla erecta) photographed in white light, showing the visual pattern of this image as perceived by humans. Image number BP4531 shows...

Tormentil (Potentilla erecta) photographed in ultraviolet light, showing the visual pattern of this image that is visible to bees and butterflies. Ima...

Fig Buttercup (Ranunculus ficaria) photographed in white light, showing the visual pattern of this image as perceived by humans. Image number BP4533 s...

Fig Buttercup (Ranunculus ficaria) photographed in ultraviolet light, showing the visual pattern of this image that is visible to bees and butterflies...

Common Fleabane (Pulicaria dysenterica) photographed in white light, showing the visual pattern of this image as perceived by humans. Image number BP4...

Common Fleabane (Pulicaria dysenterica) photographed in ultraviolet light, showing the visual pattern of this image that is visible to bees and butter...

Lineworkers doing electric powerline construction in Camas County, Idaho, USA.

Lineworkers doing electric powerline construction in Camas County, Idaho, USA.

Lineworkers doing electric powerline construction in Camas County, Idaho, USA.

Beaver Dam built in a stream in the Boise National Forest, Idaho, USA.

Electric concept car public exhibition in front of the Hotel de Ville in Paris, France.

Electric concept car at a public exhibition in front of the Hotel de Ville in Paris, France.

Electric concept car public exhibition in front of the Hotel de Ville in Paris, France.

Electric concept car public exhibition in front of the Hotel de Ville in Paris, France.

Electric concept car public exhibition in front of the Hotel de Ville in Paris, France.

Electric concept car public exhibition in front of the Hotel de Ville in Paris, France.

Scarlet Peacock Butterfly, Anartia amathea, Butterfly Magic, Tucson Botanical Gardens, Tucson, AZ.

Ancient Cliff Dwelling at Palatki Heritage Site, Ancient Cliff dwellings built by the Sinaqua - ancestors of the Hopi Indians - about AD 1100 to 1300,...

Love-in-a-mist (Nigella damascena L.), Poulsbo, Washington, USA.