Quagga were hunted to extinction after the Dutch settled in South Africa, they were killed for both their hides and because the quagga competed with domesticated animals (horses, cows, goats) for forage. The Quagga became extinct in the wild in 1878, there were some quagga taken to zoos in Europe where they attempted to breed them, but the attempts were unsuccessful and the last quagga died in captivity in Amsterdam on August 12, 1883.
There are currently a group of scientists trying to bring the quagga back through a program of selective breeding of Burchell's zebras, which are the closest living relatives of the quagga.
Sigerson was a name Sherlock Holmes used during the period when he was supposed to be dead, following the events of the story "The Final Problem."
Oxytocin is also used to induce labor in humans.
Sherlock used the name Sigerson for an ad. Sigerson Holmes is the character name used by Gene Wilder in "The Adventure of Sherlock Holmes' Smarter Brother"