Spine (Philadelphia Pasadena Edition)
1995 Feb 1;20 (3): 379-383.
Division of Neurosurgery, Department of Surgery, University of California, San Diego, California
The bone at the end of the spinal column is called the coccyx, from the Greek word for the cuckoo bird: kokkyx, kokkygeus. The earliest, undated use of the equivalence between kokkyx and cuckoo appears to be in early Greek mythology. (1) A mountain in Argolis had the name Coccygeus given to it because there Zeus metamorphosed into a cuckoo bird, possibly in one of his amorous escapades, implying the laying of eggs in some other bird's nest - typical for many, but not for all members of the cuckoo family.
Vesalius gave this avian derivation of the word "coccyx" (25) without naming its originator. Hyrtl (9), physician, anatomist, and philologist of Vienna of the late 1800s, wrote that Herophilus coined the term because of a fancied resemblance to the beak of this bird. The etymologic designation also was credited to Herophilus by Skinner (22), but without any obvious source.
Herophilus: The Coccyx and the Cuckoo
Herophilus was born in Asia Minor, at Chalcedon in Bithynia, not far from the Sea of Marmora and the Bosporus. The volume about Herophilus by the classics scholar, Heinrich von Staden, gives life-dates of about 330 BC to about 260 BC, and reasons for the uncertainties. (26) He was one of the first Greek physicians to come to Alexandria, to the "Mouscion" founded by Ptolemy 1 (called Soter, the preserver). This most trusted of the Greek generals of Alexander the Great took over Egypt when Alexander died in 323 BC, and made Alexandria its capital. The "Mouscion" comprised a series of buildings with lecture halls, laboratories, observatories, a library, dining halls, a park, and a zoo. The name originated from consideration of the nine Muses of Greek mythology, patrons of the arts and sciences. Herophilus and his occasional rival, Erasistratus, were able to do many dissections of humans, some of which, according to Latin-writing physicians Celsus (ca. AD 30) (2) and Tertullan (AD 155-222), actually were vivisections, although this too has been a matter of considerable dispute.
Just how Herophilus came to make an analogy between the bone at the lower end of the human spine and the beak of the cuckoo bird is unknown because there are no extant writings of this Greek physician. Any such writings he may have made or had a scribe make, and that would have been kept in the library, would have been destroyed in the great fires in Alexandria, which occurred in 48-47 BC, when Julius Caesar was besieged there, and in later wars that culminated in the final destruction when the Arabs invaded Egypt in AD 640. Celsus apparently had access to these writings and referred to many findings by Herophilus, crediting him for naming the duodenum, the calamus scriptorium in the floor of the fourth ventricle, and other structures, including the torcular or "wine-press," now more prosaically named "confluens sinuum." (2) However, Celsus did not ascribe the word coccyx (for the lower end of the spine) to Herophilus nor to anyone else. Von Staden (26) rigorously applied the criterion for a work or description of writings by Herophilus, that they should be specifically attributed to Herophilus by another writer who presumably had access to them [e.g., Rufus, Galen, et al).
Rufus of Ephesius (fl. about AD 115), perhaps the first great etymologist of anatomic terms, described the sacrum and added, without naming a source: "and one gives the name of coccyx to the end of this bone." (3)
Singer and Rabin (21) noted: "How it came to be applied to a bone is a mystery, but it is so used by Galen." Galen (AD 130-200) appears to have had access to the writings of Herophilus, directly or through some intervening author. The multi-volumed set of Galen’s writings, edited by Kuhn, (10) described the end of the spine in this manner: "The sacrum is composed of three parts, to which a fourth bone, called the coccyx, is added." This description is clearly not based on the human skeleton, but from that of a monkey, commonly termed "the Barbary ape," (Macacus inuus, according to Singer, (20) who remarked “It should be understood that he [Galen] …