Howard Dietz disease. Howard Dietz Howard Dietz (September 8, 1896 – July 30, 1983) was an American publicist, lyricist, and librettist. Dietz was born in New York City. He attended Columbia College and then studied journalism at Columbia University. He also served as publicist/director of advertising for Goldwyn Pictures and later MGM and is often credited with creating Leo the Lion, its lion mascot, and choosing their slogan "Ars Gratia Artis". In 1942, he was made MGM's Vice President in Charge of Publicity. He held that position until his retirement in 1957. He began a long association with composer Arthur Schwartz when
Artis Library library was able to stock its shelves. In 1881, librarian Gilles Janse compiled a catalogue of the Artis Bibliotheek’s collection holding 4,381 items. The Artis Bibliotheek grew to include more than 16,000 titles. From 1848 to 1995, the Zoological Society Natura Artis Magistra published the journal "Contributions to Zoology". All issues of this journal are now in the Artis Bibliotheek collection. Initially, Westerman kept many of the library’s items in his home; the collection, however, has been housed in its own building at the zoo since 1859. In 1868 the collection was moved to the building on the Plantage Middenlaan.