John Ray applied one of the previously more general terms for fixed natural types, "species," to plant and animal types, but he strictly identified each type of living thing as a species and proposed that each species could be defined by the features that perpetuated themselves generation after generation.
John Ray brugte en af de tidligere mere generelle vendinger for faste naturlige former, "arter", til at gælde for planter og dyr, men han identificerede udelukkende hver type af levende ting som en art, og foreslog, at hver art kunne defineres ved funktioner, som fastholdte sig selv hver generation .