The primary objective of this thesis is to identify patterns of appearance among the flora and fauna of selected eighteenth-century New Spanish casta paintings. The objectives of the thesis are to determine what types of flora and fauna are present within selected casta paintings, whether the flora and fauna's provenance is Spanish or Mexican and whether there are any potential associations of particular flora and fauna with the races being depicted in the same composition. I focus my flora and fauna research on three sets of casta paintings produced between 1750 and 1800: Miguel Cabrera's 1763 series, José Joaquín Magón's 1770 casta paintings, and Andrés de Islas' 1774 sequence. Although the paintings fall into the same genre and within a period of a little over a decade, they nevertheless offer different visions of New Spain's natural bounty and include objects designed to satisfy Europe's interest in the exotic.