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History of Medicine

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Banner containing six icons that link to the individual pages of the website. From left to right: 1. Image of three embryos, that links to the Embryology page. 2. Image of conjoined twins from a 15th century book, that links to the Age of Superstition page. 3. Image of Millie-Christine McCoy, that links to the Marvels on Exhibit page. 4. Image of Clara and Alta Rodriguez, that links to the Separation Surgeries page. 5. Image of a fine engraving of two sets of conjoined twins, that links to the Gallery of Images page. 6. Image of a title page, that links to the bibliography page. Below the banner, to the left of the links to each page is a large eighteenth century woodcut illustration of female twins joined at the back. From 'Monsters' to Modern Medical Miracles: selected moments in the history of conjoined twins from medieval to modern times. Embryology and Classification of Conjoined Twins Age of Superstition Marvels on Exhibit Separation Surgeries Gallery of Images Bibliography

Marvels on Exhibit (15th through 18th-centuries)

Chang-Eng Bunker

Nineteenth century advertisement for Chang-Eng Bunker’s exhibition tour, circa 1832. It shows the twins dressed in a specially made Chinese-style suit that reveals their connecting band. They are standing on a stage beside a bench and table on which is a chess board. One holds a badminton racquet, while another badminton racquet and shuttlecock lay on the bench.
Nineteenth century advertisement for Chang-Eng Bunker’s exhibition tour of England, circa 1832. It features an illustration of the twins dressed in a specially made Chinese-style suit that reveals their connecting band. They are pictured standing outdoors in front of a palm tree and tent. In addition to the details of when and where they will be on exhibit, the text gives a brief biography of the twins, explaining that they have passed their nineteenth year and are in full health. Moreover, they have been visited by the Royal family and ladies and gentlemen of distinction who have expressed their satisfaction with the exhibition.

Chang-Eng Bunker were born on May 11, 1811 to Chinese parents in Siam (Thailand). At the time their birth was viewed as a portent of disaster and the Siamese king Rama II initially ordered them put to death, before becoming convinced that the twins themselves were harmless. By their teens the twins had found favor with King Rama III, who showered them with gifts and even sent them on diplomatic missions. A British merchant, Robert Hunter, and American sea captain, Abel Coffin, convinced Rama III to allow the twins to go on a two and one-half year exhibition tour in America and England from 1829 to 1831. Shortly after this tour Chang-Eng took control of their career and earned a living as entertainers for the next four decades.

Center image from a nineteenth century lithograph, showing Chang and Eng Bunker standing in a specially made suit that reveals their shared band. Surrounding the center images are nine additional images that show Chang and Eng engaged in various activities of daily life, such as driving a carriage and fishing. Also pictured are their wives and children.

Touring the world, their stage presence, and their uniqueness made them famous in very little time. Many marveled at the thick, fleshy ligament, five to six inches long and eight inches in circumference, that connected them at the base of the chest. Despite the prevailing societal idea that conjoined twins were monstrous, inhuman beings, Chang-Eng became accepted and respected by society, and were often received by royalty.


At age 28 Chang-Eng settled down to be farmers in North Carolina, where they married the Yates sisters in 1843 and maintained separate households. The couple produced 21 children between the two families, though only 11 survived to maturity. Financial necessity compelled Chang-Eng to return to show business and make paid public appearances. In their later years, they often appeared with their children, which both piqued audience curiosity and demonstrated their humanity. On their return voyage from Russia in 1870, Chang became paralyzed from a stroke, which required Eng to support him physically for the remaining three years of their lives. Chang-Eng died on January 17, 1874, at the age of 62.

Autopsy Report on Chang-Eng

With the widows' permission, a detailed autopsy of Chang-Eng was conducted by Drs. William Pancoast and Harrison Allen in the Mütter Museum of the College of Physicians of Philadelphia from February 10-11, 1874. Shown below from the autopsy report, are a contemporary sketch of the bodies and a diagram illustrating the conjoined tissues and hepatic vessels of the connecting band. Given the shared hepatic vessels it is doubtful that a skilled 19th-century physician could have successfully separated the twins without causing the death of one twin.

Sketch made by Dr. William Pancoast of the bodies of Chang and Eng Bunker, after their autopsy in 1874. The autopsy incision and connecting band is clearly seen.
Nineteeth century illustration of Chang and Eng Bunker’s livers and shared hepatic vessels, showing how an injection into Chang passed into Eng.
Nineteenth century illustration detailing the peritoneal and hepatic pouches and ensiform cartilages in the connecting band of Chang and Eng Bunker.

Millie-Christine McCoy

"The Carolina Twins", Millie-Christine McCoy, were born in Columbus County, North Carolina, on July 11, 1851 as ordinary slaves. Both girls were remarkably healthy although Millie would always remain slightly smaller. Between the ages of 10 months and 6 years of age, the twins were sold at least three times (legally and illegally) and exhibited throughout the United States and England. Millie-Christine were frequently examined by physicians in the towns where they appeared to confirm that they were conjoined. The physicians were astonished to find a pair of conjoined twins of African American descent. They were described as interesting, intelligent people who had nothing of monstrosity in their appearance.

North Carolina merchant Joseph Pearson Smith purchased Millie-Christine's parents and family from the McCoys and his wife taught them how to read and write and sing and dance. They became fluent in five languages and were accomplished pianists, singers, and dancers who toured the world. They were frequently billed as "The Two-Headed Nightingale" after their beautiful singing voices. In 1869, the twins issued their autobiography, "History and Medical Description of the Two-Headed Girl," which was purchasable for $.25 at their public appearances.

Title page from the pamphlet entitled, “History and Medical Description of the Two-Headed Girl,” published in Buffalo by Warren, Johnson, & Co., in 1869. It says that the pamphlet was “sold by her agents for her special benefit” for 25 cents.

After a successful thirty-plus year career, the sisters stopped performing in shows and retired to their home in North Carolina. In 1909 a fire destroyed all their possessions and they suffered great financial loss. The twins' health also began to decline. Millie contracted tuberculosis, which later affected Christine, and eventually claimed both their lives on October 8, 1912.


Physical examination of Millie-Christine

Nineteenth century profile drawing of Millie-Christine McCoy as adults. They are dressed in period-syle stockings and boots, and draped in cloths that cover their fronts, but reveal the conjoined area at their buttocks. They also appear to be hunch-backed. The twins are each looking to the side; one has her eyes closed.
Nineteenth century illustration of Millie-Christine McCoy’s shared genitalia, showing one set of labia, one vagina, and one uterus, but two separate urethra.

In 1871 while touring in Philadelphia, with Chang-Eng Bunker, Millie-Christine were sent to Dr. William Pancoast to be treated for an anal fistula. He published details of his examination, including photographs and sketches of their conjoined tissues in the Photographic Review of Medicine and Surgery. His examination confirmed what other physicians had already determined: Millie-Christine shared one vulva and one anus, but had separate urethras and bladders; the labia majora although connected to two clitorises, ran continuous across the vulva and protected but one vagina and one uterus. He characterized the band of their union as containing mostly cartilage with shared osseous tissue at the sacrum.

Last Reviewed: March 11, 2024