Article: The football team plays at Ryan Field (formerly known as Dyche Stadium); the basketball, wrestling, and volleyball teams play at Welsh-Ryan Arena. Northwestern's athletic teams are nicknamed the Wildcats. Before 1924, they were known as "The Purple" and unofficially as "The Fighting Methodists." The name Wildcats was bestowed upon the university in 1924 by Wallace Abbey, a writer for the Chicago Daily Tribune who wrote that even in a loss to the University of Chicago, "Football players had not come down from Evanston; wildcats would be a name better suited to [Coach Glenn] Thistletwaite's boys." The name was so popular that university board members made "wildcats" the official nickname just months later. In 1972, the student body voted to change the official nickname from "Wildcats" to "Purple Haze" but the new name never stuck.

Now answer this question: What was the official nickname of Northwestern's athletic teams prior to 1924?
The Purple