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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

Gallery of Images

Embryology and Classification of Conjoined Twins

Nineteenth century drawing of 5 embryos of conjoined twins showing the partially separated germ segments.

Diagram of germ layers in embryos of conjoined twins, 1889.

Nineteenth century drawing of twins joined at the crowns of their heads.

Craniopagus: joined at the cranium (head).


Age of Superstition (15th-18th centuries)

Fifteenth century woodcut illustration of female twins joined at the chest.

Locher, Jacob, 1471-1528. Carmen heroicum de partu monstrifero. Ingolstadt: Johann Kachelofen, after 26 Nov. 1499.

Sixteenth century woodcut illustration of female twins joined at the back.

Paré, Ambroise, 1510?-1590. Deux livres de chirurgie. Paris: André Wechel, 1573.

Seventeenth century engraved illustration showing two views of female ischiopagus conjoined twins joined in the genito-urinary area.

Liceti, Fortunio, 1577-1657. De monstrorum caussis, natura, et differentiis libri duo. Patavii: Apud Paulum Frambottum, 1634.


Eighteenth century woodcut illustration of female conjoined twins joined at the back.

Aristotle, pseud. Aristotle's compleat master piece, in three parts. The 29th ed. London: Printed and sold by the booksellers, 1772.


Marvels on Exhibit (19th century)

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.

Early publicity illustration in color

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.

Exhibition tour handbill

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.

Currier and Ives illustration


Photograph of Chang-Eng Bunker, seated, with two of their children, standing.  All are well-dressed in suits.

Chang-Eng with two children

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.

Sketch of Chang-Eng's autopsied bodies, 1874

Nineteeth century illustration of Chang and Eng Bunker’s livers and shared hepatic vessels, showing how an injection into Chang passed into Eng.

Diagrammatic representation of Chang-Eng's shared livers


Nineteenth century illustration detailing the peritoneal and hepatic pouches and ensiform cartilages in the connecting band of Chang and Eng Bunker.

Peritoneal pouches in the connecting band of Chang and Eng

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.

Millie-Christine autobiography title page, 1869

Nineteenth century profile drawing of Millie-Christine McCoy as adults.  They are dressed in period-style 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.

Illustration of Millie-Christine McCoy


Nineteenth century illustration of Millie-Christine McCoy’s shared genitalia, showing one set of labia, one vagina, and one uterus, but two separate urethra.

Close-up of Millie-Christine's shared genitalia


Separation Surgeries (20th century)

Photograph of newborn ischiopagus twin girls, Clara-Alta Rodriguez, being held by a nurse shortly after their birth.

Clara-Alta Rodriguez, shortly after birth

Photograph of Dr. C. Everett Koop standing over a hospital bed in post-operative recovery, where the separated Rodriguez twins lay, side-by-side, draped in hospital blankets.  Clara, on the left, is awake; Alta, on the right, is sleeping.

Dr. Koop with the twins in post-operative recovery

Photograph of the recently separated Rodriguez twins laying side-by-side on a hospital bed.  Clara, on the left, is draped in a hospital blanket; her eyes are open; she is looking at her sister and holding her sister’s IV.  Alta, on the right, is in a hospital gown; her eyes are closed, and her head is in a plastic chamber.  Courtesy The Children’s Hospital of Philadelphia (NLM UI 100961905).

Clara and Alta in post-operative recovery


Dr. C. Everett Koop stands at a whiteboard, on which he has laid out the details of the surgery for separating the Rodriguez twins.

Koop explains the surgery to the press

Close-up of Dr. Koop’s whiteboard notes detailing the surgery that will separate the Rodriguez twins.  In addition to a rough diagram showing the shared genitor-urinary area, the notes include the equipment needed for anesthesia and the surgeries; the known surgeries to be performed (cytoscopy, vaginoscopy); the surgical decisions that will need to be made regarding the bladders, rectum, and perineum; and a list of the staff assigned to each twin.

Close-up of Dr. Koop's notes

Dr. C. Everett Koop stands in a hospital room holding the separated Clara and Alta Rodriguez in each arm, prior to their discharge from the hospital. Both twins are wearing dresses and have bows in their hair.

Dr. Koop holding the separated twins


Clara and Alta Rodriguez stand side-by-side, holding onto a white table on the patio at their home in the Dominican Republic.  Courtesy C. Everett Koop (NLM UI 100961905).

Clara and Alta at home in the Dominican Republic ca. 1975


Note: All images displayed in the separation surgeries section may be found in the C. Everett Koop Papers at the National Library of Medicine and are the courtesy of Dr. Koop. Images of the separated twins taken at the hospital are posted to the website by permission of The Children's Hospital of Philadelphia. Every effort was made to secure the permissions to post the other images, but the current copyright owner either could not be identified or could not be contacted. If you have information regarding the copyright owner, please contact us at hmdref@nlm.nih.gov.

Other Images

Seventeenth century engraved illustration of two sets of conjoined twins.  Thoracopagus twins (joined at the chest) are at left;  pygopagus twins (joined in the lower back) are at right.

Liceti, Fortunio. De monstrorum caussis, natura, et differentiis libri duo. Patavii: Apud Paulum Frambottum, 1634.