This cluster of reproductive cells within a fern won second-place.
This is third place: a spittlebug nymph huddling inside a protective coat of bubbles.
Ever seen a peacock feather this close? This is the fourth-place winner.
No. 5: A spider embryo with its surface in pink and microtubules in green.
No. 6: The central part of a primate's retina.
No. 7: A dried human tear drop.
No. 8: A portrait of a very grumpy-looking mango seed weevil, or Sternochetus mangiferae.
No. 9: A security hologram.
No. 10: A pair of stalks containing pollen grains.
No. 11: A human fibroblast, which is vital for the healing of damaged organs, undergoes cell division. (DNA is stained magenta.)
No. 12: Scales on the wing of a Madagascan sunset moth, or Chrysiridia rhipheus.
No. 13: An acorn barnacle.
No. 14: A cell from an African green monkey stained to show it's hidden structure.
No. 15: A mite on the back of a honeybee.
No. 16: A mouse's oviduct, which serves as the site of fertilization.
No. 17: Breast tissue, with milk-filled spheres (in red) surrounded by muscle cells that squeeze out milk (in yellow), and immune cells that detect infection (in blue).
No. 18: Crystallized amino acids — the molecules that make up genetic material.
No. 19: Ouch — an Asian hornet with venom on its stinger.
No. 20: The layers of a human retina that enable people to see.
Nikon Small World also recognizes "honorable mentions" that didn't make the top 20, but were close. Here's a Daphnia water flea full of eggs.
Sea angel larvae use cup-shaped mouthparts to feed.
The mold Penicillium vulpinum can grow with surprising symmetry.
The shell of a lychee fruit that's illuminated from within.
The wing of an emperor butterfly.
A cross section of a Bosnian pine tree.
Cloth fabric (in red) and bubbles on the surface of a rock.
Because there are so many good images, Nikon Small World has a third category called "images of distinction," which follow. The category includes this picture of a Wonga Wonga Vine. It's a popular garden plant found in Australia and the southwestern Pacific region.
Dye-injected nerve cells inside a mouse's brain.
Cyclop, a one-eyed water flea, with eggs.
The surface of aluminum milling grooves.
Part of a brain with nerve cells in red, nuclei in blue, and tau proteins in green.
Sex organs and support structures of moss.
Eek! This is the tip of a tarantula's fang.
A fern's reproductive cells.
The underside of a decaying northern red oak leaf.
Fluorescent protein in a living HeLa cell, which is the oldest human cell line used in scientific research.
A dried-out drop of blood.
Golden algae found in freshwater.
A segmented worm with movable hairs.
A mouse embryo stained for motor nerves (in red), sensory nerves (in magenta), and nerve endings (in cyan).
A rotifer — a microscopic aquatic animal — feeding.
Almandine, a type of mineral from Hubei, China.
Iron oxide needles on quartz in Ontario, Canada.
Part of a cat's tongue showing blood capillaries.
A parasitic larva from a wasp family feeds on a spider abdomen.
Human neurons from Parkinson patients.
A ball of plastic microfibers found drifting in the ocean's plankton.
Microtubules in cells from veins of a human's umbilical cord.
Mite on an antenna of a May bug.
The early development phase of a tea-leaved willow's male reproductive part.
Marine organisms called dinoflagellates taken from a culture of algae.
Neurons of a mouse's inner ear.
A 3D reconstruction of a mouse testicle (in green) and blood vessels (in red).
A thistle tortoise beetle.
Sea urchin larva found in marine plankton.
Single-celled marine organisms that grow on seaweeds.
The inside of a mouse eye. Fibers (blue) help suspend the lens at the center (red).
Layered crystal faces of smithsonite.
Transport tissue in a buttercup root.
The iris of a human eye, with a "freckle" shown in blue.
A wilted flower.
Nikon Small World also awards winners for its "Small World in Motion" video contest.
See all of those winners here.
Disclosure: Dave Mosher, one of the authors of this post, was invited to judge the Nikon Small World competitions in 2017 and 2014.
