Every genus is natural, created as such in the beginning, hence not to be rashly split up or stuck together by whim or according to anyone's theory.
Systema naturae (1735) (quoted in Ramsbottom 1938:197) Original in Latin: Genus omne est naturale, in primordio tale creatum, hinc pro libitu & secundem cujuscimque theoriam non proterve discindendum aut conglutinandum.