Hoefnagel had chosen 'natura magistra' (nature his teacher) as his motto. It reflects his interest in the realistic depiction of nature. He made a start with his miniature drawings of animals before he left Antwerp. It is on the strength of these early miniatures that he was appointed by the Dukes in Munich. Gradually these natural history were organised into a four-volume manuscript (various folios dated from 1575 to 1582 in various museums including the National Gallery of Art, Washington, the Kupferstichkabinett Berlin, the Louvre, Paris and various private collections). The work was entitled "Animalia rationalia et insecta (ignis); Animalia quadrupedia et reptilia (terra) ; Animalia aquatilia et conchiliata (aqua); and Animalia volatilia et amphibia (aier)" and contains detailed depictions of thousands of animals divided according to the four elements. The book is therefore simply referred to as the "Four Elements"). The book is made up by about 300 miniatures accompanied by about a thousand inscriptions.