The photographs feature fish that have been specially treated to make the stained skeletal tissues visible through the skin and flesh. The technique, developed by Dr. Adam Summers, uses dyes, hydrogen peroxide, a digestive enzyme and glycerin to make the flesh seem to disappear. Photo: This image of the butterfly ray (Gymnura crebripunctata) helped scientists study the joints in its wings. (Photo by Adam Summers)

Kaw-Claa, a Tlingit native woman in full potlatch dancing costume, 1906. (Photo by Case & Draper/Buyenlarge/Getty Images)

Full length portrait of female skier, Sierra Nevada Mountains in California, USA. (Photo by Anatoliy Gleb/Getty Images)

A full moon rising over the Re Island Bridge in Rivedoux, France is pictured on December 14, 2016. (Photo by Xavier Leoty/AFP Photo)

Conjoined twins Angelica (C) and Angelina Sabuco (L) play with child life specialist Allison Brooks during a press conference at the Lucile Packard Children's Hospital at Stanford on October 31, 2011 in Palo Alto, California. Two year-old conjoined twins Angelica and Angelina Subaco who are connected at the chest and abdomen are preparing for separation surgery by Dr. Gary Hartman. The surgery will last between 6 and 8 hours that is followed by three hours of reconstructive surgery for each girl. (Photo by Justin Sullivan/Getty Images)

People in full medieval armor take part in a combat at Central Park in New York, U.S., August 14, 2021. (Photo by Eduardo Munoz/Reuters)

A full moon is seen behind buildings at night in Ashkelon, southern Israel on December 1, 2020. (Photo by Amir Cohen/Reuters)

Burdened with a shawl full of her belongings, a woman stops for a rest on the road between Julaca and Puno in Peru. (Photo by Three Lions/Getty Images). Circa 1955